BJ's Wholesale Club review: Discount applied

Before Christmas, I purchased a gun safe, normally it is $599 but had it on Sale for $299 so yeah that was super HOWEVER, I was charged the full $599 and in Erie County, New York I pay 8.75% tax, so I paid $52.50 in tax then the $300 is taken off. I went to the manager to say what’s this, and he said I don’t know, just always has been like that, so I asked;

1) Does it benefit BJ’s-NO
2) Does it benefit the consumer-NO
3) Does it benefit the tax man-YES
So I again asked why, and he had no clue, but he took my number and said he would call me, been almost a month and no call.