iPhone 5 help

I have an iphone 5 and I have a serious problem. My iphone wastes a lot of data. I keep my data turned off so I won't have overages. Most of the time I just turn on my data and get on Instagram for like 2 minutes and then turn off my data. I then check my data by typing *3282# and my data usage is up by about 20mg. I have have everything that uses data off even iMessage. Is there a way to fix it? I'm on AT&T thanks!
Welder is offline Report Post

What exactly did you do in those 2 minutes in Instagram, did you upload pictures? Dd you view a bunch of other people's pictures? Also, when you enabled data and were using Instagram other apps in the background or iOS itself was probably doing some work as well..

What is your data cap?

I guess I review a lot of pictures, but i did that before.

Are you under the impression that loading a lot of pictures doesn't use data?

20MB sounds perfectly reasonable for someone who is "reviewing a lot of pictures" on Instagram.