AT&T wireless AT&T lied about upgrade Nationwide

In January of 2015 we noticed that alot of apps on our smart phone was starting to say that it was incompatiable, we had the phones for 4 years, so we decided to upgrade. We talked to AT&T and chose our phones and asked them if our bill would change because we were upgrading and still keeping the same share plan. They said no that our bill would  be the same if we didnt change the plan. Well our bill went up $50 a month on our next bill, so my wife called and they said that we signed a new contract and that we lost our old plan  becuase of it and that we were actually saving more money with the new contract. They said that we were lied to and that they were working on getting rid of reps that were lying but there was nothing they could do otherwise.