Wear and tear or damage/loss?

Tenancy Deposits

Tenants have been in house for 9 years. My late husband managed the property (as I am disabled and have chronic fatigue and mobility problems). they always had a very low rent as they were saving for a deposit to buy and also refused rent increases because they promised to fix anything they broke themselves - this was after we refused to replace a range cooker and a shower - 3 of each broken in 3 years. 
I agreed to them moving in to another property I own 2 doors along (I used to live there and they've always had ambitions to but previously couldn't afford it)as they have always paid the rent on time...my own decision but I'm regretting this already as they've installed a satellite dish without permission (it's a no in the AST) right above the front door on a very pretty house. If I'd known the true extent of the work needed in the house they've just vacated I wouldn't have allowed them to move into another property I own. There is even more potential for that to be ruined as the garden is 3 times the size, it has more bedrooms and bathrooms and everything is new.

The house they've left is in a terrible condition. It wasn't perfect when they moved in as we'd not had time to get carpets fitted downstairs as they needed to move in urgently. The floors were however stripped and waxed.
This was 9 years ago but the house had been stripped back to brick for damp treatment and re plastered and redecorated throughout. So a new kitchen was installed, appliances, stove and tiled floor, t&g splash backs, beech worktops (never again) new shower and basin in bathroom, everything else newly decorated,new carpets and all clean. 

Having allowed them access for an extra week once they moved their belongings out and reminded them to read the AST regarding cleaning and the opportunity to do repairs in the house and garden several weeks before the end of the tenancy (by email)...I found they've done nothing... except white wash (patchy and grey, one coat) the whole house which wasn't their job anyway - only a sitting room needed to be returned to its original white colour as they'd painted it dark grey.

So check out inspection was a shock. It would have been impossible to see the state of the house before it was empty as they had so much furnicture and belongings, although the garden was visible from neighbouring properties and was overgrown. 
The (was new) garden shed is missing, the rear gate blocked with rubbish under a pile of tree branches, what was a lawn is now an area of strimmed thick stemmed weeds, mud interspersed with brown dead grass. No shrubs left and borders strimmed weeds, all still in the ground. 
mud has been splashed up the white outside walls, drain is full of rubbish, lots of broken plastic in garden. 
Inside, there are new holes through walls from cables in every room, huge stains on all carpets, all woodwork dirty, one door missing, one door split. The kitchen worktops (advice on maintenance and Swedish oil was supplied) are black with water damage, one split through, all have been stained with a mahogany colour which also reaches a cm up the t&g white splash backs. All cupboards are filthy, sink unit has collapsed, tap is loose, range oven and cooker hood are thick with grease. Floor tiles are cracked in both doorways into kitchen, and one bathroom floor tiles] is shattered. Bathroom basin is cracked and bath and toilet are badly stained, all skirting boards in bathroom are water damaged.
There's more but by now you're probably feeling great about your own tenants!

So, the check out inspection didn't go well. Apparently the shed had no roof felt so tenant lawnmowers and bikes were damaged (I have photos and it was covered in felt), apparently it's my fault I didn't replace carpets in 9 years or kitchen units or redecorate every room. They blame my late husband for breaking the kitchen sink unit and the cracks in bathroom basin and kitchen sink...very unlikely and if he did he would have replaced them immediately. There has been a lot of blaming my late husband but I can vouch for his attention to detail as he was dressed ready to visit this tenant (to follow up several texts and phone calls he'd received) on the morning we found him dead on the sofa. 
The tenant thinks the lawn was mowed 'enough', that they were looking after the worktops, that the cracked basin, sink nd tiles had been there for ages, that all the dirt and greasiness is wear and tear.that the missing shed and blacked gate, rubbish in garden, holes in walls, stained carpets, missing lawn and shrub borders are all wear and tear...they were just living there and that's what I should expect. 

Apparently I'm being unreasonable, apparently they've never been a burden to us (I did reply to that by saying the state of the property and the work and time and money it will take to make it presentable for new tenants IS a burden) and they don't want this to come between us as they think a lot of me and my children...really?
I know I've made mistakes - I will send someone to inspect the house they've moved into every few months and advise on their responsibilities regarding garden, cleanliness and any damage. I have a lot of photos and film of the new property and a full inventory and I've only supplied a stove not appliances.

I must still have a video film of the house they've left but that will be difficult to locate. I do have invoices for contractors just prior to them moving in and for new kitchen carpets tiling etc.

However since this tenant is vociferously defending themselves over the state of the property they've left for me and actually cried and left before check out was completed....and insisted they've had to put up with repairs not being done (not true) no decoration or new carpets in 9 years (they didn't want them or a rent increase) and the kitchen wasn't perfect when they moved in (it was new) etc

DOES ANYONE HAVE ANY ADVICE? 

They are really wearing me down and making me question whether I am at fault, but I think the AST is clear and I'm not expecting too much. 
I have been business like about the check out and check in and preparations/responsibilities for them. I've sent reminders of the procedure, what documents are needed, what clauses in the AST are relevant etc but they seem to have ignored most of this. I was a tenant once and my children have been tenants in different properties for years and none of us would treat another persons property like this or delay the chance of landlords getting new tenants in this way.

Replies welcome.