Smg Cape pathetic service

Took my 20 year old 318ti there for a oil seperator to be changed as the car has full service history with the agents. My car goes in with no faults absolutely quite engine but when it comes out of that place my dash displays brake lights, abs and traction control which they do not want to take responsibility. I then go speak to them they reckon to me the faults was there before but the lights were not showing. Then they also tell me to sort the problem out there will be 3 stages I have to sort the problem out. If the problem is not sorted out at the first stage and if needs that it will be all 3 stages the damage cost would be 60k. All of a sudden my engine is a bit noisy and they tell me my chain Is loose. Had i taken my car to a back yard mechanic I would of not have this problem.