Bad service

On the 26 Aug 2015 I dropped off my car at the dealership after it didn't want to start and there was a funny noise when I start it.I was told I will get the car by Friday , Monday and the Thursday.Mark called me on Thusrday that he drove test the car and it's fine the only hong left is to submit paperwork and he will call me back.He called me back and said there was a problem with the paperwork as in June I paid whilst the car was still under motorplan.He said he will call me the following day as he had to explain through e-mail why I paid and he needs some time to sort it out.He further told me I will probably get it on Monday.I made a follow up AGAIN and he said he called their HO and that they will call me back of which they didn't .I feel enough is enough as I'm being inconvenienced by someone's incompetency whilst they have their own cars to drive around.I requested that I have my car back whilst they sort out the paperwork and Mark indicated that if I take it it will be at my own risk.Im just not happy and disappointed that such a reputable dealership can treat customers like that.? :(((