Unfortunately I don’t believe there are any good choices in Turkey for Afrocentric hair. Some people (Rarely) got lucky with HOI, Asli Tarcan and Heva but they are hair mills and should be avoided. Just because they have strong marketing and seemingly good reviews on unreliable sources (Yelp/Trustpilot/FB/Insta etc) they manage to get a lot of traction.
What you need is someone who is actually skilled and had proven results with Afro hair, so guys like Dr Mwamba, Dr Bisanga, @DrTBarghouthi, Dr Feriduni and maybe Dr Lupanzula. You will still find the occasional miss, but absolutely nowhere near the same rate as a unknown tech working at one of the above hair mills.
Trawl the forum, and look elsewhere too, don’t trust any one opinion and just try and see for yourself who is actually able to do good work. Look for actual patient posted review’s accompanied by pics, reach out to them and check they are genuine.
Longevita are not one of these that excel in Afro hair (or any other) they are a middle man.