There is nothing that I could find in the West Virginia Code that prohibits carrying a firearm or deadly weapon into an establishment that sells alcohol, or into a bank or credit union.
Your friend is wrong. There is so much bad information floating around it boggles the mind.
I just now put up my research on the sections of the West Virginia code that relate to firearms (owning, carrying, possessing, etc). While it is not complete, it does provide links to things like the definition of concealed, that you may not carry a loaded firearm in a vehicle without a license and some of the other laws that are on the books.
I've only found 1 instance where open carry is specifically mentioned in WV code. That doesn't mean there aren't more, it just means that so far I've only found 1.