Originally Posted by
gleff
OMG. My darn Diners Club points have ALREADY POSTED to Delta. No getting them back into an account where they're worth something.

Well, at least it would be hard for DL to claim that you initiated the transfer after you already knew the promo was terminated/"changed".
Maybe you'll be successful in getting your bonus miles eventually.
Good luck.
Originally Posted by
mirobatka
I think we should't confuse "changing the T&Cs" and not honoring them.
...
P.S. The rules even said that any changes would be posted and made public within those rules, so if they pulled the plug that's OK, but they should suck up the mess they have created so far.
Exactly. DL can end a promotion early (going forward), but it can't retroactively cancel it. That's not a change, that's more like false advertising/fraud.
Furthermore, as you say, participants need to be notified of the changes. They have our e-mail addresses and they have a website they could use to provide such notification.