I have been charged a fee for shipping that Customer Support refuses to reimburse or credit. This was for a replacement phone to be shipped to me when mine stopped working.
UPS (not my choice of carrier) failed to deliver the phone correctly for 4 delivery tries - I finally got it 8 days after the initial delivery attempt. I think T-Mobile should not pay for the delivery service and I should not be charged. It was a very frustrating experience. Not only that, but Customer Support was so unhelpful and unsympathetic when I called to contest the charge.
I felt really unvalued and disappointed in the company.