Gamecenter error: connecting to online services on call of duty black ops zombies for iOS.

So I got this new app 3 months ago called Black ops call of duty : zombies. And I LOVE it!! But every time I try to join an online game, wether it be map vote, single map, 2-4 players, restarting my phone... What happens is it takes me to the gamecenter connect page, where it connects me with another player, but after a few seconds, it takes me into the multiplayer lobby, and then pulls up a message saying "connecting to online services" and it does that for a minute before saying "error joining room" and makes me quit the online game, leaving the other person kicked off the server because the other person (me) left or was kicked, I do NOT want to jailbreak my iPhone for this problem, and I am very experienced with iPhones and other electronics, both apple and Microsoft, if there is anyone who knows how I can fix this problem WITHOUT jail breaking my phone or paying money.. (Maybe ill pay money, it depends...) then Please tell me! It has done this to me EVERYTIME for the past 3 months, and still does... So please help!