When a dispute is filed the bank will issue a provisional credit the same or next business day if the dispute meets certain criteria. I forget the exact details on when you do and don't get a provisional credit right off the bat but basically boils down to the only situation in which you wouldn't get a credit would be where it's not a dispute over whether the charge was authorized but one over whether the goods/services were delivered because in those cases the bank has to give the merchant a chance to tell their side of the story or make good or whatever. I forget if this is a Visa/Mastercard network policy (they homogenized the rules between credit/debit cards awhile back and it might have been part of that) or a regulatory one but the end result is that you're only without money for a day if there's an unauthorized charge.