Dealer wont do the paperwork

[Aberration79]

Hey guys. So I purchased a suppressor from Primary Arms in February. It got shipped to the local at the beginning of April. They have been a complete pain in the ass. I have already done an SBR and a suppressor, and I was well aware of what 41F was doing. I won't get into all of it, but to this day they have still not sent in the paperwork. I walked into this place with all the paper work done, I just needed their information for the forms. They insisted upon charging me $100 for them to do it.

What can I do? Personally I would like to just get a refund, but thats a bit more complicated with a suppressor and one shipped from the seller to just a middle man. I have no idea where to go from here.