Need a proper Toyota diagnostic shop near the industrial area – any leads?

I'm in a bit of a pickle with my 2015 Camry – the engine light came on last week and the car's been idling rough ever since, but the weird part is it drives completely fine once you get going. I took it to a local garage near my place in Mohammed Bin Zayed City and they charged me 150 dirhams just to plug in their scanner, told me it was an oxygen sensor, replaced it, and the light came back on two days later with the exact same code. At this point I'm convinced they just guessed and hoped for the best, which is incredibly frustrating because now I'm out money and still have the same problem. I work not too far from Musaffah Industrial so I'm thinking of taking it to someone who actually knows what they're doing, specifically a professional Toyota service and diagnostics near Musaffah Industrial that won't just throw parts at the problem without proper investigation. Has anyone found a workshop around that area that really takes the time to understand these Japanese cars? I'm honestly getting tired of paying for other people's trial and error, and I just want someone competent to sort this out once and for all.