I'm not a lawyer, although I have played on on TV.... (j/k)
First, taking a step back, it's difficult to say that I actually have damages. Chase can cancel my account anytime they want, for any reason. They didn't confiscate my points (although I presumably will lose the 7% bonus).
But let's ignore that for a moment.
Contract law is complex, full of rules and exceptions, but the principal principle is a meeting of the minds. A party to a contract doesn't have an inherent right to exploit an unintended loophole nor an error.
There are also questions of agency and other principles I don't know the right names for, but they basically say that up to a point, a company is bound by the actions of its employees and independent agents, but no further.
So if I had exploited an unintended loophole or an error (but what was it??) or there was a rouge CSR at Chase, Chase could repudiate the action. But there are two further questions here:
1) What actually took place at Chase? It's not believable that Chase was infested with rouge CSR's willy-nilly making T&C-violating transfers; it almost has to be true that Chase trained their CSR's to do it. Remember too that in litigation (including formal administrative procedings), parties can't just shrug their shoulders and say "Gee, I don't know" or "That information is privileged." If I were to sue, I would be entitled to engage in discovery, including suboenaing relevant documents and deposing relevant witnesses, and while a judge would not let me go hog-wild, he would surely require Chase to turn over copies of the training materials given to CSR's, and any changes therein. And while individual personnel actions would probably be deemed overly invasive, I would quite likely be allowed to ask "Of the x CSR's who made the transfers, how many were subjected to disciplinary action as the result of these transfers?" Chase can't claim the transfers were "errors" or "loopholes" if they trained the CSR's to do them and didn't discipline them for doing them.
2) In cases of loopholes or errors, a party can usually invalidate a contract, but not go beyond that. If you book a mistake rate at Hyatt, can Hyatt cancel your Gold Passport account?
The fact is that all of us occasionally have something get a bug up our ***, and this one is up mine.
Now here is the part that will be interested.
The day afte they closed my account, I applied for an Ink Bold,which I had been planning to do anyway. They deferred the decision, and today I got a all from Chase Business Lending. A few questions about my business, and I was approved! (Questions: Age of business, revenues for past 3 years, profits for 3 years, my total income.) I will be quite interested to see whether I can transfer my UR points from my old account - to my new one!