No Service on 3g

[iduhfs]

I bought a phone on CL with just the apple logo boot screen. I messed with it and now everything seems fine but I get no service (I have atnt). Sometimes it shows bars at zero, and sometimes it just says, 'no service.' Here's what I did to get here:

1) Install 3.1.2 (7d11) with redsnow (still just boot screen)
2) Install 3.1.2 (7d11) with shift-restore in itunes. (worked)
3) ReInstall 3.1.2 (7d11) with redsnow

The phone was supposed to already be unlocked and used on t-mobile. Now I have:

3.1.2 (7d11)
BB 05.11.07
Bootloader 05.09 (so no rolling back the bootloader)

I want it jailbroken but I don't particularly need it unlocked, though I will if it's straight forward.

Where should I go from here to get atnt working?

[mavrik101]

Download Blackra1n to your computer and run it . That will jailbreak your phone. If you want to unlock, add source in cydia (blackra1n.com) and run Blacksn0w.

[iduhfs]

Thanks Mavrik101, worked like a charm.