in a quick note a need a certified rotary mechanic in or around san diego that can help me with my car

thats the short version long story is

i took my 95 to a place called zwhizz because i have a aftermarket warrenty so i have to have a qualifed shop work on the car. so it over heated one day and i took it into them and they changed the heater hose and some caps and said it was fine so i got the car back and drove it around 100 miles and it over heated again and the oil pressure had issues too. each time it over heated i pulled over let the car cool then filled it up with coolant or water to get home with. so i take it to them the second time which is a week and 100 miles later and they said now it has failed a block test which means that exhaust gases are getting into the coolant so the engine is shot and i said well you guys can pay for my new engine because you didnt fix the over heating problem which is why the engine went out and they are not going to do anything so im going to go to small claims court and need a certified mechanic to help my case so please please help