LGS messed up my handguard?

[jfornelli]

Update:
I went in to the shop today, ready for a battle. It ended up being the owner that approached me and asked if I needed any help.
When I told him who I was and the situation, he was fully versed on it and said they're ordering a replacement and will take care of everything. It did end up being the tabs that go into the barrel nut. They've installed several of these and have a lot of experience with builds and even have their own line of some products.
So, all in all, their intentions are good with me so I'm happy (though it will be just that much longer before I have my build complete).