I'd be surprised if it wasn't frozen after only 48 hours, all of my shipments from Big Cheese have arrived frozen after 72 hours, they usually take 3 days to arrive. Ship Monday, they get there Thursday, ship Tuesday and they get there Friday.

I used to refreeze twice, but after losing one of my rainbows boas, I either don't refreeze at all or refreeze only once and only furred rodents. We never figured out what exactly caused it, but it's mostly likely her last mouse caused the blood infection that killed her in some way. You can't always tell when a feeder is bad, either, it may smell perfectly fine and still end up killing your snake.

As long as the prey doesn't sit at room temp, refreezing once shouldn't be much of a problem. If they're above 40-50F (read with a temp gun), then I'd throw them out and get more.