orrrrrrrr...do what i do when this happens...hang up the pump and start again...same money is being spent just 2 transactions...
A lot of the ones around here won't let you do two consecutive transactions on the same card. You have to move to another pump or use another card.
Also, it still does it regardless of debit or credit. I just try to refill before I dip below the 1/4 mark.
It sucks people can't be honest, and pay after getting gas. They wouldn't have stopped doing the gas up, then pay thing.