Just what we did, just bought a Turkish mobile in the Turcell Shop.
This makes me laugh, my daughter's Father in Law went into a shop in the U.K and asked for a phone, well just a phone, he did not want the internet or messaging, just a phone that he could make calls and receive calls.
He was told there was no such thing... We told him he needs to come to Turkey as they have just the phone for him... We have it and we love it.
Basic story, buy a cheap Turkish mobile, no headaches in the long run. if you have a maintenance company, leave it with them to look after for you.