Mastercard Gift Card review: gas payment / poor customer service

A Mastercard Gift Card worth $25.00 was offered as payment for a gas purchase totaling $29.33. The location took place at store #1325 and the transaction # was 503417. The dark haired girl entered $29.33 and as you can assume, the $25.00 gift card was declined. She informed me that the card was not valid in front of a line of customers. When I presented her with the validation receipt from the store where is was honestly paid for, she said simply that I wold have to check with Mastercard, but find another payment method at the moment. I called Mastercard when I got home and the card was ready to use, and had the full $25.00 on it. I then, as I had kept the declined invoice (#115945) noticed that she had attempted to charge the full $29.33 on the $25.00 gift card. I went back a couple days later, as the situation bothered me, and successfully used the same Mastercard gift card to make a purchase of slightly less than the gift card total $25.00!