Very unprofessional

Very unprofessional! A mechanic came out to do the inspection and explained to me what needed to be done. The next day, a different mechanic came out to replace a different part as to what was said by his colleague, and the wrong part was ordered. The next day, the part was replaced, but the error persisted as the mechanic did not clear the error messages on the electronic system. When I phoned to explain the error - the person I spoke to was very rude and shouted at me saying that they did nothing wrong, but admitted to all of the above, and proceeded to hang up on me. The problem has not been solved and after spending thousands of rands on inspections and parts and I had to take it to another servicing department to have fixed what Michanic messed up!