It used to be that if you wanted a home phone, you had to rent it. Then, in the mid 80's, deregulation opened things up and made it possible for people to buy phones, but some people continued renting and didn't realize it. A class action lawsuit involving 10 million people was settled for $300 million, but some people are still being surprised by the charges. Some people don't even realize they're renting the phones, until they change services and the phone company asks for the phone back.
If you would like to learn more about your phone bill charges check out the Federal Communication Commission or the National Consumer's League. The United Seniors Association also has valuable information, and if you feel you have been wronged, you can file a complaint.