If the Petco vet hasn't even considered surgical repair, you need another opinion. It's a pretty minor surgery with a decent success rate, but there is no guarantee of success of course. And the more frequently this little one prolapses in the meantime, the less likely surgical repair is to be effective.
Please do use the ARAV link above to see if there is a reptile veterinarian in your area. Even if there is not, you can try to set up a telephone consult with one (just offer to pay for it like a regular appointment).