TopDogDirect.com review: I do not want to be recharged any amount.

I purchased a Beactive+ (knee brace) which arrived with a credit card on the internet. I assumed the total amount was charged to my card. On 09/10/22 I received an email stating the sales tax was not added and my card would be recharged $2.40. I called to talk to customer service because this was not my fault and I should not have to be recharged for their mistake. I was also trying to find out how would the situation be handled if a customer had mailed a check in for this product. She told me they would contact the individual and ask for the sales tax to be mailed in. I wonder who would mail them the extra fee. It is not the small amount that concerns me; it is the fact that this company made a mistake and just because they have my credit card in their system I get recharged. It seems to me that is poor business on their end.