Aircon - not fully repaired

complaint - poor quality of work and problem not resolved - Aircon Vehicle taken to Bosch Car Service Springfield Park , Durban 4 times to repair the aircon, still not yet resolved , on the 4th occasion I was advised that the cannot understand what is wrong and could not pick up the fault , vehicle taken to another specialist and issue was picked up in 5 minutes , parts previously replaced by Bosch is actually working and did not need to be replace, Bosch needs to refund my payments. Absolutely appauled that a so called reputable company cannot resolve and identify an issue with an aircon.