need my money back

wanted to buy a car changed my mind when i realised how much of a rip of it was then when it was time for them to give me back my deposit people dont remeber talking to me or even sending me emails they ignored me when i drove there twice to ask he told me i got your email its done that was last week monday stil no money today? i sent emial after email since the 10 of september he only claims he was notified of my case on the 17 but i have emails from even before then i sent another one today telling them i want my money or i will take action now he is ignoring me saying i threatened him there phone lines are down and he only replys to emails when he wants to and on top of it they still get to take 4.400 of my money for canceling the deal