It definitely looks like you missed out. I would suggest calling MR Customer server and get their help with getting it cleared up. They should have also paid for your first night at the other hotel as well. So if they didn't do that, you should get even more.

If you a Plat, then you should have either received more points or the certs plus the $100. Someone, in another thread, recently noticed the same discrepancy you have found. And right at the moment, I'm not sure there is a definitive answer. The T&Cs did state you should have received the points, but at least one webpage was recently updated with the certs information.

Note that Marriott used to offer Plats certs and those certs were very nice in that they were usable at virtually any Marriott hotel worldwide and were NOT dependent on award availability. So they were much more usable than an award cert would be. But of course some might prefer the 90K points instead as those would add to your existing account balance.