Hi there,
I second TB's post. It sounds like some type of spinal deformity, and if the snake is eating well and acting fine it may be nothing to worry about.
However, I would suggest visiting the vet for a check up and x-ray to see the animal's bone density, so that it can be certain that it is simply a congenital deformity. Although it is less common in snakes than in lizards, a nutritional or renal metabolic bone disease can cause spinal deformities as well, especially at a young age.
I would definitely let the breeder know of the situation. It would be important for him/her to know that a possible congenital deformity occured in their offspring, so that in the future they may consider a different pairing.
If it does turn into something more serious and costly (and you act on it and don't let it worsen) and you have it documented in a veterinary file, you may be able to use that as leverage to get a partial or complete refund if you bought it as an explicitly "healthy" animal. It is possible of course that they knew about it and sold it to you anyways... But I like to think the better of people
I also like to try to think that herp breeders have some morals and ethics, although all animal breeder "classes" have their good and bad ones.
Keep us posted and good luck,
Christina