I recently booked a vacation at the St. Kitts Marriott Resort & The Royal Beach Casino for next year. I decided to use points and pay for an upgrade to an ocean suite. I was quite shocked when I saw double the points charged to my account. When I called the hotel the agent said they remembered discussing the additional points deduction with me. Of course that is exactly what they are going to say but I had all my notes from my disucssion and no where did I have DOUBLE the amount points notated. The agent was adamant that she discussed this (NOW of course to say herself) and I mentioned that this large amount of points would have been an eye openner to me and I would of had this amount in my notes. I am not to happy now and clearly not looking forward to this vacation next year now.
There is a couple of options you might try to solve this issue.
First, look into making a new reservation for the same as you booked previously, and do not call the hotel you should be able to book it all on Marriott.com including the upgrade to the ocean suite. If that does work then simply cancel the other reservation and watch for the points to be refunded to your rewards account shortly afterwards. Of course this won't work if the property is sold out of those type upgrades etc.
Second, call Customer Service and explain the situation....a nice friendly chat usually works fine.
Best of luck in getting this resolved and do let us know. I will also give a shout out to our MI gang (jmart, The specified item was not found., merb & ansaa) so they are alert to this issue should you not get it resolved simply.
if you are using a Marriott travel package, make sure you don't use the word, cancel. Just postpone or reschedule, so that they will redeposit the travel package back into your account, otherwise they will cancel the travel package and only redeposit a fraction of the original points you paid for the package (travel packages can be a good deal, but involve convoluted accounting).
if you are not using a travel package, but straight MR points, then no problem with canceling the reservation, since it's way in advance. You will get your points back, and you can start over, preferably with a knowledgeable, competent associate who can get you the points + cash upgrade that you seek.
Best wishes for success and a memorable vacay.