Ok, here's where me and Sols are going to differ, and he's going to assert he knows best.

Question one, are the company estopped from making a claim because you relied upon their statement that you could claim? I'm not sure, because I don't know how much you told them before they paid out. Neither does Sols, but he's certain I'm wrong. That's an interesting position to take on the basis of so little knowledge. If you told them nothing about the injury predating the operation, then I'd guess you're in a weaker position than if it's documented that you told them everything and they simply changed their minds.

Second; would a judge apply equitable principles if a claim for restitution were issued by the company? Sols says the insurance company are 'obliged to consider your financial position and health'. Those are equitable considerations. So we seem to be asserting the same thing but sols doesn't recognise some pretty basic legal language and principles. That's interesting.