Avis turkey was the worst for me.
I took the car, a terrible Focus with over 80k kms on the clock, it had to be 5+ years old. Driving from Istanbul to Cannakle, about 4 hours. it started to rain and behold I found the wiper plades were ruined! I had to stop, buy new ones. Avis refused to compensate me even though i gave them the old ones as well, on top of that they charged me twice the forecourt rate to top the car up and billed me for 4 wheel trims stating damage when there was none. all compliants went through Avis turkey and i got nowhere with them.
on the other hand everywhere else has been excellent service with Avis so i continue to use them