T-Mobile BILLING DISPUTES-OVERCHARGES Bellevue, Washington

I had an additional line that I had from April 29, 2011 to April 30, 2011.  I returned the phone to a Radio Shack other than where I purchased the phone.  I obtained the receipt for return of the phone from the store.  These people did not cancel the line.  After spending more than 3 hours on the phone with T-Mobile and numerous trips to Radio Shack, with no success, I ported out the number just so the line would cancel out!  

These people billed me pro-rated charges until the port out date of May 4, 2011 and then had the audacity to bill me for one day of service (May 4, 2011) for $49.99.  I made a call to them, they manually credited back the $35.00 but did nothing about the advanced charges.  

I have made 2-3 calls to these people already and they are not willing to budge on this.  I am extremely livid that I even had to pay the pro-rated charges and then an additional $49.99 for a phone I never used.  I purchased the phone, came home, found out it was USED and took it back the next day.  

I do not know what the problem is with this company.  Do they think they can rip off the public because AT&T is taking them over?  I am so angry.  I would strongly advise that EVERYONE steer clear of this company unless you feel like baby sitting your bill every month.  This company is the worst.  The coverage of their service isn't even worth it.