Iphone4s slow gaming

[Serbian]

I got an iphone 4 and a 4s and everything is perfect except SL. I get 15mbps download and 4.2mbps upload and my connection is always on full. When i go on youtube, lightning fast, open emails or surf net ots lightning fast....play SL and its slooooow like crazy. I get pings of 500 just standing still. I know its not my network because i tested on iphone4 and iphone4s and both have issue with SL and are light ing fast everywhere else. Any way to fix this? It wouldnt bother me much but i spent like $100 on platinum and would like to enjoy an enhancer without being kicked out of a game 10 times during one run.