My control buttons do not work!

This device is not recognized or common.

You have two options:

First disassemble the device and see how built the part that does not work, buy it and just replace. (To be sure it is the correct part!)

t-mobile work with htc and they produce for them the phones so that the parts may have bought your phone from t-mobile will not be identical to that model which is not t-mobile.

Or just go to t mobile that will fix it .. they sure have parts for your model.