Unlocked iPhone 5 SIM Invalid

So right now I am on T-Mobile and just a few days ago my GS3 broke so I went ahead and picked myself up a factory unlocked iPhone 5
Now when I was buying the phone, I met up with the seller, who actually owned his own iPhone repair shop/unlocking company sort thing, the phone was an AT&T iPhone that he said he had unlocked himself (like I said he unlocks phones for a living) and he said that it should take between 1-6 hours for the unlocking process to finish. I bought the phone at 6:30 and he did whatever means necessary to get the phone unlocked (all that IMEI stuff idk...) and as I type it is 11:43 and whenever I try to plug it into iTunes to activate, it still says my SIM is invalid...

now here is what i question
1. Did the unlocking process not go through? He showed me on his computer his little unlocking website and the status of the unlock on my phone said "pending" when I was picking up the phone at his shop.
2. Could it be my simcard? He did cut my simcard and idk if the simcard got effected, but regardless I plan on picking up a T-Mobile nanosim tmrw.

Should this be happening? How long does the unlock usually take on average anyway? I'm quite the impatient person, and I have class tmrw and I won't be able to get a new sim till way later if my sim is the reason why my phone won't activate -____-