I'm pretty new at this, but I never had a failed feeding. Before offering it, I would keep the rodent in a plastic tub with air holes, a hide, a tube, water, and some morsels of food to make the rodent comfortable. I would then coax the rodent into the snake enclosure and watch until it got too close and was struck and wrapped. I'd stand by as it happened and would put the tongs in the rodent's mouth until it died so it couldn't bite my snake even if it had the right angle to do so. If I couldn't see the rodent's head, I would move the snake so I could see it.
If you want to try again with the hopper, maybe try getting it comfortable, relaxed, and fed before offering it again. I wouldn't though. I imagine that it was a traumatic enough experience for it to know that seeing the enclosure and the snake means mortal danger.
Maybe the store you got it from would take the rodent back for credit? My local store offered to in case my BP ever declined to eat a live prey. I have no interest in a pet rat or mouse, so I definitely would've taken them up on the offer if I ever needed to.