I don't know how to link to earller threads, but thepla posted this on 2/29.

"Thanks for the help. I did call customer service and Marriott does have the equivalent to the "Challenge" available to AA. It is 12 stays in three months for black and 17 for platinum. I will send a letter to see if I can expidite the status."

So maybe if you call again you will get a better answer or can ask about the challenge.