Micronics Group Study

The Abu Dhabi summer is no joke and my AC decided to quit on the hottest day of the year. I am desperate to get it fixed quickly but I also do not want to rush into a place that will just recharge the gas without checking for leaks. I have been asking around for quality automotive repair solutions that specialize in AC systems because I know this is not just about adding refrigerant it is about finding the root cause. Some workshops quoted me very low prices which makes me suspicious they will do a temporary job. Others are asking for much more but I cannot tell if that is justified or just expensive. Has anyone had their AC completely redone recently? What should a proper diagnosis and repair actually cost and how do I know they did it right?