FINAL UPDATE:
Just went in and met with the GM this morning. He apologized for what happened and cut me a check for a replacement. Also told me that due to their recent move into their temporary building, none of the security cameras were up and working. However, they had issues with their new porter for other things already and this was enough for them to release him. They're still looking more into his background but firmly do not believe it was any of their techs, which I'm inclined to believe as well. Lastly, he apologized for the phone call I received from the service mgr Friday (which was what really set me off to begin with) and said he shouldn't have been the one to call me, nor tell me what he did at the time, especially that he'd already spoken to GM and that was simply conveying the msg that they wouldn't be investigating.
I'm usually a pretty good judge of character and can smell bs from a mile away, but he really did seem genuine in the things he said, particularly the fact that he hopes I'll be going back to them in the future, but wouldn't be surprised if I chose not to. At this point I feel like they've done enough on their part for me to be satisfied w/the situation, at least as much as possible. I still do not like the fact that my pistol is out there somewhere, and I also don't like that I now feel like I can't trust their establishment in the way I used to, but it is what it is and certainly a lesson for me as well.
For anyone here who has left a negative review/comment on the FB page, I would appreciate if it was amended/deleted, I wouldn't feel right not asking that.
Once again, thanks for the support that was out there for me in this situation, and please keep an eye out for my beloved OD Glock. Thanks everyone.