Northcliff Auto BMW has a Bad Service

I sent in my 2013 BMW F10 528i For repairs as it was shaking / jerking on Idle and it had an oil leak and i was told the shaking is caused by the leak on the head gasket and was charged 8.8K to fix the issue, I collect the car and the car still has the issue it was not fixed and they said they tested the vehicle and drove it. i sent it back again now the say it is a turbo problem and coolant leak and i was quoted 15.5k they took a full week doing that when they finished with the job they found that the problem was still not fixed and they now said its a bad fuel injector which i was charged 6.8k which i told them to claim it on my extended warranty but they sent in a wrong claim to the warranty people and the claim was rejected and i had to call the warranty asking why the claim was rejected only to find that the claim was wrong i fixed that issues and claim was approved. Collected the car after a few day with the car i could smell burning oil checked found that the is an oil leak in the car again, i take it in and the mechanic says its leaking some where else not in the same place where they worked on. i am being charged again. and every-time the car goes in they always include the charging the battery cost. Northcliff Auto Bmw has a really bad service they just want your money and do the worst job on your car