Aidpage

i want to know if you get another provider with a cell phone do you every have to pay the cancellation fees for the old provider if you paid up the minutes and usage of the phone carrier this dates back to 2008 when they said if you get a new provider and show proff no cancellation would apply to your service agreement in the state of michigan .
i got a call from a debt collection service stating i owed ove 986.00 on a phone cancellation charge it blew me away here when i paid the use age and time for the bills and i asked them to give me a new phone because the phone was not working the right way they didn't want to provide me a phone free of charge to use there service but they continued to bill the cancellation fees to me when they told me it would not happened to me and they wont stop bugging me either they have threatened me telling me they were going to turn it over to the trw and report it when i did not get anything for this this is not right it should not be legal and binding when the minutes and usage was paid for in full! and i went in to show them i had new services too ... what should i do to make them stop bugging me here.