I have experience this 3 times inside of 2 years with 3 different carriers as my XXXX condition required 2 moves. 
This was a XXXX where I purchased the phones that claimed they would work in XXXX they did not- although there map of coverage and customer service claimed it was within the coverage areas. 
Purchased cell phone plan- cell phone provider was unable to meet the requirements of data services, coverage. Numerous calls to report missed calls, dropped calls, poor service or no service in areas that they claimed had service coverage. 
After months of calling customer service and complaining I cancelled my contract due to them not holding up there end of the contract- at that time I was told I could not do that and they would take immediate legal action. 
I figured since they said they were taking me to court I would n't have to do any of the filing and it was on them- surprise it went to collections.