My point is that they paid a one-time appearance fee, which resulted in massive publicity for their event and region, and in people coming and spending more money than they would have. Thus, they got their money's worth for the fee.
Now, they look like fools for having paid a cheating scumbag liar huge sums of public cash, but I'm not sure you can sue for your money back if the person you paid got the results you wanted, at the time.
Would Trek have the right (and the gall...) to sue him for his salary & bonuses? Wouldn't they also then have to reimburse everyone who bought a Trek because of Lance? And, they had an on-going contract with Armstrong, not a one-time deal. (Assuming that Trek didn't know the truth, which is inconceivable)
Mind you, I hope they do sue, and I see your point. I just think that they don't have much of a leg to stand on. And I'd also like to see them go after Rann & Turtur as Ferminal suggested.