Is there no fix for this?
I had someone call in recently with the same problem, different phone. What I did was resync sdat and cancel location while they reset their network settings on the device, then power cycle. Not sure which did the trick, but it seemed to fix the problem.
I can't make any promises, but it's worth a try.
Hopefully you can get a rep who can understand the instructions, the resync sdat option is located in Grand Central under T-Mobile ID (you need to have your My T-Mobile account set up for the option to he available to the rep). I apologize for the jargon, but the rep will (should) know what you're talking about.
You can reach your Team of Experts by calling 611 from your phone, use the Message Us link on this page, or contact T-Force via Facebook or Twitter.
Good luck and let us know how it goes!