Anyone know a decent garage in Rolla that won't rip me off?

I just moved to Sharjah from Dubai a few months ago and I'm still trying to find a trustworthy mechanic near the Rolla area. My 2014 Nissan Sunny needs a major service and the AC isn't blowing as cold as it used to. I've driven past maybe ten different garages on Al Mina Street but honestly I have no idea which ones are honest and which ones will see a woman coming and quote triple the price. A colleague at work mentioned something called Expert Auto Care Rolla but she couldn't remember exactly where it was or if they were any good. I don't mind paying fair prices for good work, I just don't want to be taken advantage of. Does anyone here have a go-to garage in Rolla or nearby that they actually trust for Japanese cars? I'm looking for somewhere that does proper diagnostics instead of just guessing and replacing random parts. Also it would be great if they have a waiting area that's not just plastic chairs in the sun because I usually have to wait while they work. I really appreciate any recommendations from people who've actually used these places, not just driven past them. Trying to avoid the trial and error method because my AC can't wait much longer in this heat.