AT&T Wireless Sold me a phone knowing I was in an area they don't reliably service Fort Collins Nationwide

In July I moved to a location that had inadequate cellular service.  I went to the AT&T stores because I've been with them for more than 20 years.  I gave them my new address and they sold me a new phone, saying the old phone was the problem. 

I worked with them for 6 weeks, during which they tracked my calls and tower connections.  Near the end of the six weekss the tech person on that call said he had "a book" of files he had to read through before helping me.  I'd driven back to their store 2 or 3 times so they could fiddle with hardware and they finally replaced the SIM cards.  But it didn't work.

I was losing jobs because people couldn't reach me by phone and since it didn't work, I didn't have Internet either.  Eventually I had  CenturyLink DSL service connected so I had the Internet.  Then AT&T tells me my only option is to spend another $150 to buy a "micro cell" and that it required Internet access to work.  So, in addition to the cost of the phone and service, they wanted $150 for that micro cell and I had top pay for broadband service to the microcell would work.

When I dropped them they said they'd hit me up with early cancellation fees which later turned out to be a falsehood because I had no service contract.  They wouldn't take the phone back and are coming after me for the $200 price tag they had on the phone.  I had kept the phone because they were confident they could get things working. When they failed to do this they said the phone wasn't returneable outside of two weeks.  But I tried returning it immediately, when they ran out of ideas to make it work.