Any of you guys out there having a problem with your credit card customers. I've had 5 people call me over the past 6 months who said i've overcharged them for a sale. After calling up the Credit card processor, they are telling me that some cardholders accounts automatically have a 20% gratuity added on to the sale. & if there is no gratuity, the money is refunded to the customer. For example. customer orders and gets charged $10. They check their balance online the next day and it says $12. Then the money gets put back within 24-48 hours. The sale then goes back to $10 This makes absolutely no sense to me. The customers call up and they're accusing me of overcharging them, and they're upset. What if they had almost nothing left in the account, NSF, overdraft sets in. This really isn't fair to the customer. Anyone else out there dealing with this? Anyone out there in merchant processing can answer to this?