Many of us here aren't trying to attack you, we only want what's best for the snake. Seeing an injury like this with no apparent cause is of course going to be shocking and upsetting to the people here, who devote so much time attention and passion to creatures just like what you have.
The most important thing you need to know about your situation is that reptile breeders are not veterinarians. Quite frankly I don't think they're very good breeders if they didn't shoo you off to a reptile vet as soon as you showed them this animal. I wouldn't buy a single snake (or anything else) from someone who thought letting an animal this badly damaged sit around and heal on it's own was the best course of action.