[rtb]

Yes, a metaphor for doing it "even more". He means that they will be angry and will do more than just reverse the transaction: they will punish the merchant who fraudulently debited your account. They will levy a fine on them (any merchant who is plugged into the ACH system will have signed a contract with their bank agreeing to accept such fines and possibly put up a bond), or even perhaps ban them from making any future transactions, seriously harming their business.