3600 and 3650 Frequency Differences

I have a Nokia 3650 on T-Mobile. I unlocked it so that I could use it on Cingular. I get no service for Cingular when I insert their SIM at home, but it works 50 miles away at work. After doing some research, it appears that Cingular's signal is at 850 or 1900MHz. The 3600 is designed for this, the frequencies for the 3650 are 900, 1800 and 1900 MHz. Is there any way I can get my 3650 to pick up 850 MHz?

Not without extreem hardware modification

I wouldn't bother with it if I was you
better to by another network sim

much cheaper and you cannot fu*k your phone beyond repair