Help unlock my phone, how to please

[jazzo]

Chaps, I wonder if you can help me at all. I have a samsung spica gt i5700 and a few months ago I flashed the firmware so now I have android 2.2 on it. Yesterday I changed network provider and moved to 3 (from Tmobile) so my tmobila number will be unusable tomorrow the latest. What the idiots at tmobile failed to tell me is that the phone is locked to a t mobile simcard, so I can't use the other sim. I need to unlock the phone so I asked t mobile and they want