Harassment

Hello, I need to file a complaint against T-Mobile for harassment.  I left their service a few years ago and even though I didn't have a contract with them at the time, I paid off the $68.00 that they say I owed.  After that time, I received another bill that said that I had to pay close to $400.00 to have the bill paid off.  I sent them the last bill for $68.00 and yet they are not honoring what they said they would in their letter.  Their collection agency has been calling me for money for months since I left their service, and on top of that, they are calling me on my business line that I just had put in 2 weeks ago!  I asked them how they got the number since it is unlisted, and they did not tell me.  Every time they call, I tell them the same thing, that it was paid off and then they say o.k., well we won't bother you again, than they do!  I need to get these people off my back!  Please help...what they are doing is totally illegal!  Thank you for any help that you might be able to assist me with.  Have a nice night.

Kerin McCurdy