company let, rent arrears, breach of contract, end of tenancy

Guarantor

If he refuses to replace the inset and hearth can I approach the company and pursue them? Does the contract still stand? It was made in 2007 - the company is still trading as a registered charity - but has just moved address and changed number. The tenant does become threatening and aggresive and also lied and said the company had ceased trading. I have spoke to the father in law on a couple of occasions and he has been polite and helpful - but it then results in a tirade from the tenant. The contract was drawn up by an estate agent and is a company let agreement.

It was an open fire - it probably just needed the chimney sweeping, however he never gave me that recourse of action and the property has GCH and he did not have to use the fire at all for heating purposes, It is a feature of my property that I like and I wanted to keep as I did when I originally bought the property and renovated it!

any views or thoughts would be gratefully appreciated.