The microphone in the smartphone was replaced in a couple of hours. They were quick, neat, and polite, and the price was 65 rubles, which is a bit expensive in my opinion, but there are more expensive ones in Minsk. The microphone is working, and the callers can hear me again. They gave a 4-month warranty.
Diagnostics are free of charge in the event that repairs are required and it will be carried out in the same service. If you do not need repairs or want to pick up the device and install it in another place, then for the time spent on diagnostics - 25p (in another place they wanted 50p).
If you want to save up to half the amount, I would recommend that you find out after the diagnosis (look for where it is made for free or pay - it's up to you) which parts you need and order them yourself from the same Aliexpress or from the original website of the manufacturer of your equipment. But we'll have to wait 2 weeks for them to arrive. The service of replacing any parts in the equipment, if the customer has serviceable and suitable parts, is sometimes 2 times cheaper.
I live nearby, I'm glad that there is such a shop nearby, the guys do repairs and sell a lot of different household goods and mobile phones, I bought a lot of things with high quality and normal prices! I recommend.