Being in the business of keeping happy customers I agree Keystone should be willing to do more. However, from a legal standpoint, the OP could face a long and uphill battle.
IMO, the best results will come with honey rather than vinegar. Work your way up the chain at Keystone and I bet you'll get something in the way of a resolution. Bark too loudly and you could end up with nothing.
I'm in a line of work that inherently generates complaints. The easiest thing for me is when someone tries playing the A-hole, aggressive card. I have no problem showing them the fine print of the contract we have to work together. The hardest thing for me is when someone is logical and respectful. I'll do way more than I'm obligated to in order to keep them happy.