DVC laundry rooms should only be for people staying in the DVC villas and studios. Guest services at the resorts should not be sending cash guests from the hotel side of shared resorts to the DVC laundry rooms under any circumstances. If nothing else they should be referring the cash guests to the laundry valet bags in their room's closet.
Is a Visa not a Visa? Do they not issue Visa cards in the rest of the world? I know when I travel abroad they pretty much only take Visa. I wonder why the laundry company can't take a UK-issued Visa card for example. I'm really ignorant about the intricacies of international travel, I guess.