Have you already downloaded the SG4G drivers on all of your PCs? It would be odd that not even one of them worked. You're best bet to getting your phone unlocked, other than from at home, is to call T-mobile and ask them for the code. I heard they will be hesitant to give it to you if you haven't owned the phone for at least 3 months though.
As for myself, I don't know any sites that do this, sorry.