Samsung Galaxy S3 — stuck on android upgrade screen

I woke up to a greek screen I believe saying upgrade and did not accept it and restarted the phone. It came to same screen again so I accepted it. Now it is on the small android robot on the screen with a star rotating in his tummy and blue line under it and keep rebooting to that every like 20 mins for 3 days and nothing happening. I am in USA and my phone Sim in it is Turkcell, I do not have a data open. My wifi was open. I have tried Kies but it says it is not supported. I triied recovery mode and it is saying android downloading and nothing happens. I cannot choose any other options. Please help.