A rip-off

I took my Hyundai I10 to Milnerton Hyundai for a water leak they did a pressure test, the day after they let me know they have to remove the engine or part of the engine to do a diagnostic to see what is wrong at the cost of R4000+ and their experience to do the repairs it can cost between R16,000 and one ridiculous price which I don't even want to mention. I took the car to a Automotive repairs in Montaque Gardens who did a pressure test and they discovered a burst water pipe and a small part on the engine which was defective and they repaired it for R3500