have you talked with bill about this? i know i dont have the whole story but it just seems like theres been some failure in the communication somewhere, for him to build you a pack for a truck he hasnt seen, he needs as much info about your setup as possible, and you mentioned that you didnt tell them you had shackles, so im wondering what else they didnt know about that they didnt take into account when building your springs.
im really confused why you paid to have the springs rearched if they werent right from the beginning, i wouldnt have paid additional to get what i originally paid for.
asking for a 100% refund sounds a little extreme if your going to keep the springs.
and i dont think you have a case for product liability claim, were you injured?