You have given a lot of good information above but lets stick to one format to make sure everything is in context and we can pin down where the issue is. Can you send the below AT commands to the unit (in this order)?
at+cmee=1
ati
at!priid?
at+cpin?
at+cimi
at+cgdcont?
at+cgpaddr=1
at+cops?
at!band?
at+cops=? //This one will take a minute or two to complete
at+cops=1,2,"xxxxxx",7 //Replace the xxxxxx with the MCC/MNC for T mobile from the response to the above
at!entercnd="A710"
at!priid?
Regards
Matt