How to improve data quality on the Sprint iPhone 4S?

I live in northern New Jersey (973 Area Code), and my 3G on sprint iphone is insanely slow! For example, I used to be able to load instagram perfectly, but now all of the photos load low resolution and pixelated. Is there any way to fix this?

Get verizon or att. From now on, read reviews on the internet before you do anything. This was very preventable, sorry.