I think the OP meant to say retroactive points correction rather than proactive.
Always a good idea to confirm the rate and confirmation number when you check-in, and to request both a hard-copy and e-mail folio upon check-out. Sounds like they checked the OP in under the "cancelled" reservation ID? Glad the OP is joking about the chargeback -- there are several FT posts on people burned by this, as HH will gladly suspend your account and embargo all your points. I wholeheartedly agree that talking to the Diamond Desk, even over the phone, can be rather futile, as you have to explain all the details of your case from scratch every time they hand you off to a different representative.