Game center will not sign in nor will it exit

I loved playing this game on my friends iPad and was excited to play in on my computer. It downloaded really quickly but everytime I try to play Gamecenter pops up and wont sign in or when exited will pop right back up. What a waste of 10 bucks. I would like my money back or this bug fixed ASAP!

Hastetodaylikeitstomorrow about Osmos