unlocking phone

Ok this is BS we went to the store and talked to the sales people we were at&t for many years. We heard avout the deals that were less money and owned by at&t. We expressed the only reason we were with at&t was we got coverage where we kive and travel but your offer was less money. They said no problem the coverage is exactly the same sense they are owned by at&t. This was bull. Our phone will not switch mobile networks and service areas are not the same. I said I want to switch back to at&t and need the phones unlocked now they tell me I have to be with them for 6 months before they will unlock the phone. That was never discussed when we purchased and they were told up frount if they do not work we were not staying. False sales and very rude customer service when I called. They just said I need to go to the store and they will explain. In lock our phones so we can move on sense you can not provide what you said the service would provide.