U S Cellular Trying to charge me for 2 months after cancelled service, than got a letter saying they are cancelling my services, even though I already did. Nationwide

Have been a US Cellular customer since I was 18 until 1/29/2017.  Our cell phones were shut off January 28, 2017 for non payment, I called to make a payment and find out why the bill was so much. After speaking to the woman she advised me to go with another company. A US Cellular agent was telling me that the company was doing me wrong and to look else where, so that's what I told her I was going to do. I paid $220.00 of a $417.67 bill so they would turn them back on and the next day 1/29/2017 went and switched over to AT&T ending my services with US Cellular. I still got a bill for January through February and February through March but didn't have any service nor phones. Tell me how that makes sense? Then today I get a letter from them saying they are canceling my services as of 3/4/2017 and my balance is $705.90. Please tell me how 1) my billing cycle ends on the 27th switched the 29th so in February we only used two days of services and than AT&T imported our numbers from US Cellular and took their phones how I can owe a little over 700.00 when no services were used? Also they were told on 1/29/2017 that we no longer wanted services with them to send us a final bill that we were done.

They have been ripping me off for 6 years now, I went and printed every bill from them and every month my bill was suppose to be $180.00 and it was always always over $350.00 I would have to call every month and talk to someone for over an hour to have them fix my bill. Two months of cell phones were was my mortgage cost. Not to mention one of my contracts ended and I got rid of the line and than three months later an agent at the store restarted the services and got stuck in a contract for 2 years without my knowledge. I tried to fight that, even had the proof it was ended and than some how started back up, they would do nothing for me at all. I spent more time on the phone with US Cellular than I should ever had to. Got my first bill from AT&T and was $130.00 for the same amount of lines and more data than US Cellular. Please watch your bills with US Cellular they will rip you off every month and won't help you or fix it. They are just like scam artist.