Garage damagd my car

[nat]

Basically, my car was picked up from me on 17th November 2007 to have some work done on a gearbox. It was delivered back on 24th november. Since its return, the central locking hasn't worked and today I went and got it valeted and when i got home, I noticed a number of scratches were missing!
On closer inspection, you can see that the whole back bumper had been painted, the boot lid has a dent and a very bad paint job and possibly a new back light.
I phoned them this afternoon and asked if anyhing had happened to my car whilst in their care. They denied having done anyting to my car and told me to basiclly go away.
I am going to get an independant report done on the vehichles condition.
Any ideas of what I should write in a letter and where do I sand legally.

Thank you for any help in advance,

Natxx

[unhappy_c3_owner]

Hi Nat,

How did you get on with your problem?

[nat]

I am waiting for an estimate from my garage, so I can send it to them and give them 14 days to pay up.