I had the same experience at a Valero station--1 0f 2 diesel/gas stations in the area. I was filling my sons truck after a visit and had no clue what size tank it had. I was using a debit card, they asked how many $$'s--I said fill it--they said "No"--how many $$'s? I said 75.00--they charged the card immediately 75.00--I went out and filled his tank--came to 52.00--went back in--they had to credit my card back 23.00. I did check and the card was credited 3 days later. Next time I will just take "cash". But, still I would have to put the cash down and than go back in to get change. An awful lot of effort and wasted time. Lars