Help Unlocked Dell Streak 5 operating signal

[Bmendes]

I recently purchased a Dell Streak 5 and it works great in certain aspects and won't work in others. I was told to today by Tmobile (my carrier) it's because the phone uses a different operating signal (AT&T's) than Tmobile's, it won't get 3G and because of this certain apps won't run because of the data connection. Is There a way to change the operating signal from AT&T's to Tmobile's?

 

[40milesout]

no, it is a hardware issue. att 3g is on 850mhz and tmobile is either 1900 or 2100 mhz