This is a big part of the problem. They're either willfully ignorant or just outright liars, because this entire situation is the dictionary definition of racism.
Consider, however, that blacks are 13% of the total population in this country. Whites refusing to shop would likely bankrupt this business in a short time.
The store is in Savannah, Georgia, which is majority black.
The white minority is being discriminated against, as happens when blacks gain power.
In Savannah however, they are 54% (just checked). I suspect they will find that Virtue Signalling is costly as I doubt the new black customers will not be greater than the whites who go elsewhere.