Worst service from MMU group/autohaus gobel/ autohaus beyers

Bought a car in January 24. Car had overheating issues and I notified them. They took it to one of their mechanics for repairs, the guy failed, after multiple attempts, each time he would return it and claim it was fixed, only for the problem to return. 7 months later and more mechanics from their side having failed, I took the vehicle to Mercedes for repairs and sent them the quotation. I'm being sent from pillar to post, to the salesman and the mechanic, nobody wants to take responsibility. Issue is already at the Attorneys because this is just unacceptable.