I must say, T-Mobile rocks! I have been a customer for about a year and the couple of times I have had to call customer service, it has been just that...customer service. Whatever problem I had, they were able to solve it without me having to jump through hoops.
My bill with them is on auto pay so I usually just open the bill to see the balance. I had a little free time yesterday and went through every page on my bill. I found that I was being charged a $9.99 monthly fee for some unknown service. It was not through T-Mobile and I didn't remember signing up for anything.
I checked my past bills and found out that I had been charged this fee for the past 4 months. I called up T-Mobile and explained the situation. The nice lady cancelled the charge for me and then credited back the past 4 months. I wasn't expecting reimbursement for the past 4 months because maybe I or one of my cousins using my phone possibly signed up for the service. My main goal was to have any future charges stopped. I was very impressed with this and the professionalism of the customer service rep. After we were finished, I asked to speak with her supervisor. She asked if there was something wrong. I told her no, I just wanted to let her supervisor know what a great job she did. In speaking with the supervisor, I told her I know she gets complaint calls all the time so I wanted to give her a compliment call. She thanked me for making her aware of the good work of her employee and I thanked her for the great service.
Lesson: All bills need to be checked for any unauthorized charges.