The next time something like that happens you should try a few of these suggestions.
(1) Ask for the manager's business card (the all have them.)
(2) Ask for the district/regional managers contact info:
(3) Request IN WRITING a copy of the firearms policy for that particular BB store.
(4) Ask if BB follows all NC laws, statutes, etc. This applies to laws that affect customers who patronize that store.
If the manager does not want to provide the above information explain that you will pursue the matter on your own WITHOUT his assistance. Do mention that you WILL mention that the manager was in no way cooperative in resolving this customer complaint.
I had to do all the research myself after a questionable event at a local WM store. I had to call individual stores and get contact information. Some stores were not cooperative at all. Other stores just kept me on hold until they could eventually locate someone who could help me. It may not be easy, but you can get a resolution to your bad experience at BB.
Start by calling the store and requesting contact information for the district/regional managers names & telephone numbers, etc. The trick is to be "firm but courteous" in your request for information.
I hope this helps you resolve this experience at Best Buy.