Worst Car Service Of My Life

Michanic is the worst,went to service my car after service Blue smoke came out my car so I asked the Mechanic to check the problem with his diagnostic and he said it was my sensors okay I asked for the cost and I paid.They booked another mechanic to fix the problem he said it was not the sensors but the turbo so I was confused which was which so I asked for my refund since they didn’t know the real problem was, this was beginning of December every week they say Friday it’s been over 3 months now,I’m losing out on business because of them @michanic can I get my refund so I can fix my car