Originally Posted by MetaMan

gift cards and pre paid cards have a certain string of numbers to them. i forget exactly what its called id have to research it again.

but you ask your merchant to block certain ranges of numbers. there is also companies that update a list of the range of numbers. id have to find it, for some reason i cant think of the name hmmmm.

it can be done, sorry i cant be of more help off the top of my head.