Incorrect diagnoses

Talladega Auto Clinic unfortunately seems to have taken a turn to the worst. I've serviced my vehicle there several times and have been happy with the service, probably on a scale of 5, until the beginning of 2022. I took my car in for (1) a service and (2) a repair on the A/C which they gladly diagnosed for me and for which I was very grateful. At the time, the A/C provider was not open yet and the car was returned to me without the A/C being repaired, understandably. However upon getting the vehicle back the car had a new issue (the A/C blower would not switch on) and upon taking it back I was told the blower failed. I questioned this as the blower is an electric motor and cannot fail while the car is being serviced, as it should not be getting power. I was told I don't understand "electronics" so I took my keys and left. Upon diagnosing the car myself I found the blower (quoted as a R4000 part) working perfectly and tracked the issue down to a blower resistor (R1200 from agents and I repaired the failed electronic component for less than R100 myself). I'm rather unhappy that the service centre did not diagnose my issue correctly, and would not listen to reason.