problem activating droid bionic...please read/help if you can

I guess the kid I got this droid bionic from tried to unlock it for AT&T and I guess he messed it up. I tried activating it, got the 4g sim card and then when I try activating it, it says something like after trying to activate your 3g phone the 4g sim card will no longer work blah blah blah and i was talking to verizon and they were saying the kid did something to make the bionic a 3g phone and I need to try to make it back to a 4g. I don't know if that means returning the phone back to stock or what. I did a factory reset and that didn't seem to do much and I tried unrooting it but not sure if that's the problem or not. Kind of a noob here so I was wondering if anyone knew how to do this or if there's anything I can do because they were saying I'd have to mail it in to motorola and have them repair it but I'd rather have that as a last resort but if anyone can help I'd really appreciate it

As far as I can tell he modified the radio to work on AT&T. So what my suggestion would be is head over to bionic section/forum and lean how to SBF your phone. This restores it literally back to factory condition before it shipped out. This removes root and every piece of user data on the phone. This does not effect the sd.cards so don't worry about that. Hope this helps and also after you sbf you may have to take it to Verizon so they can activate the 4G sim. I don't this cause im using a DROID 3

Sent from my DROID3 using DroidForums

yea I just saw that droid bionic section haha I'm new to the site and didn't check it out good enough but thanks a lot i'll def go in there and ask about that thanks again