I bought a used car from a dealer in June 2013; however, within weeks the car had to go back for some work on the exhaust pipe. When my car was returned, it was scratched on the driver's side bumper. The dealer denied all knowledge, but eventually agreed to pay have the costs of the £150 respray. That was over three weeks ago and I am still waiting for the funds to be put into my account, how can I enforce him to pay?