Bad after sales service from Autohaus

I bought a mini Cooper S from Autohaus Gobel 6 months ago. Had my car to 5 different places to fix numerous faults.

The boot had to be close at an angle to get it close properly, wires was squashed when closing the bonnet. I thought because of this the lights would crazy when car was off. Then the ref counter stopped working, then the roof wouldn't open or close. Then the brake light stayed on when car was off. I have a whole list of problems. When I mentioned this to the sales man I got no reply what so ever. When I said the roof was leaking he said that happens with all convertibles. For the rest no answer. Also no reply after my 3rd message about these issues. I spent thousands already to get this fixed but all everyone gives me is "they have no idea what it could be". So now I am without answers with a car full of faults that I bought six months ago and now I have to take this further.