Non responsive tenant. - Possession Order.

Possession - Section 8 and Section 21

Hi Guys

Just after a bit of advice. Tenant was served Section 21 last November (14/11/2012). It was never acted upon, and she remained in the property. Last week she text to say she had vacated the property, we went round and she has left the place a complete mess, in as much as she has left a lot of stuff, rubbish etc and belongings and the house is filthy.

She left a note to say that all the items that have been left can be disposed of, however it isn't signed. We also have texts from her saying the same thing. She still has the keys. I have asked her to return them via text on several occasions, she has never answered her mobile, and I think now she may have blocked my number from contacting her. I asked her for her re-payment ID for the DPS as she is also in substantial rent arrears (over £2000).

I was just wondering now, what is the quickest way to gain possession of the house, and get rid of her stuff? are we o.k to do this even though the note hasn't been signed?

Any advice would be greatly appreciated. Thank you in advance.