I had really bad problems trying to get sterling from the Akbank atms in January with my Nationwide card in both Calis and Fethiye, the Calis one I think we managed one withdrawal and then after that we continually got a message saying no gbp available, we tried 2 in Fethiye several times think we were successful once.
I also read on fb yesterday folk had been getting charged some sort of tax ( £4 a time) for withdrawing sterling...