Deposit not protected and only partially returned... is there any point pursuing

BexInLondon

Bear with me... as this is a bit of a long one, and might be fruitless anyway. 3 girls, A, B and C moved into a house in September 2006 and paid a deposit of one month's rent. A moved out in September 2007 and was told to get 1/3 deposit from new tenant D (me!). No new AST was signed was anyone, but all parties seemed hapyp with the change of tenant. In July 2008 B moved out, leaving C, D and new tenant E. At this point a new tenancy agreement was signed, though we never got a copy of this. It was for a term of twelve months with a break clause which was subsequently exercised when we all moved out in March 09.

The inventory had been lost, and the deposit never protected, despite the most recent AST having been signed in July 2008. After lengthy correspondence we got a lot of our deposit back, though we had to pay £70 for a cleaning fee which was ridiculous since it was immaculate compared to the state on moving in.

My questions are:
1) Given that we never received a copy of the signed AST dated July 2008, could our landlord claim that our tenancy dated from September 2006, despite the fact that only one of the original tenants was in place? Does it help that we paid for a reference check for tenant E?

2) Could I dangle the threat of 3* deposit over them in order to get back the £70? (this may sound vindictive but we had a typical nightmare LA/landlord combo and I'd like them to pay for our years of an unheated, damp house and £70 would be nice).

3) Is there any chance of the 3* deposit penalty in this situation? Even if so, we'd probably not pursue it as I don't really want to stir up a can of worms now I'm safely ensconced in my own place but on the other hand £1300 each would be nice, and would hopefully teach our amateur landlord a lesson.

Any thoughts on the legal/moral position?

BexInLondon

PS I have read loads of threads on this already but not found a similar situation, hence posting the 60 millionth deposit thread. Sorry!