We are sorry to here of your lose to the circumstances you stated and if its a breeder situation as well and they are not honoring up to it, that is a shame as well.
If you have other animals (boids) start separating them into quarantine groups and medicate if possible in control environments to observe if all can carry this out and if it is IBD in each situation. If all you have is these animals from this one breeder in your collection you have started the process of gaining the right information for your claim. If you have purchased other animals from different locations and breeders you will need more positive information for your claim. As BOIDKEEPER said get a copy of what the vet stated in digital format via a scanner or take a photo and have it listed into the net on all forums you use as your proof of your stated comments. Get copies in written format of the breeder dismissing your claim, get copies of anything proving your purchase of that breeder confirming these ball pythons are from there location, emails, receipts, and shipping records. In simple terms prove your claim on all factors and from there the community will understand your claim and stand by you and black list this breeder for there negative ethics of business practices.
Many factors come into play on your situation and you simple have to prove there is in no way this is your fault. I know it sounds hard but reality is if you have been wronged you deserve to be compensated as long as your claims are 100% solid. Because anyone can make this or any claim against a breeder and breeders know this is part of the business, your only choice is serious documented proof from beginning to the end.
Well that is my 2 cents, sorry if I offended anyone, and great if I taught anyone to be more cautious on making animal purchases.