My current cellular data period usage won't reset.

So I upgraded from the 5s to the 7 plus about two months ago and when I went in to the us cellular store to get my new phone, my current data period usage was 3.4 gb. So when I restored the backup onto my 7 plus the usage said 3.4 gb. I scrolled to the very bottom and pressed reset multiple times and every time I do it 3.4 gb pops back up into the current data period usage box.. and it never changes. It's very frustrating. Someone please tell me what is going on.