Iphone 4s: legal unlock, but was still SIM-locked?

Problem:

I have a 4s that we used while in Germany. It was Tmobile, and the policy was that once we'd had it for 2 years it would be eligible to be "unlocked" for use elsewhere. I brought it back to the states and am finally attempting to unlock it. (It's unusable to us as a phone right now, we use Verizon, which uses no Sim cards, so it's all a moot point..)

I don't need it unlocked, but figured I better do it in case I lose the paperwork! I had already wiped it clean so my son could use it as a glorified iPod, and thus, there was no screen lock code on it. I thought THIS was the code they were saying to "make sure to de-activate" before resetting"

Yeah, I didn't undo the SIM lock code - didn't find any others needing to be un-done. So now, I can't get past the activation screen, and the wi-fi is wiped. No use at ALL.

Is there any hope for it? Do i need to go beg my friend at the Best Buy store to give me an unactivated AT&T or Tmobile SIM card just to get past that? So I can re-do it and do it right?

Thanks