I am staying at the CasaMagna Cancun arriving tonight for 5 nights on POINTS. Family of 4 with two small children 1 and 5. The room I am booked in is King Resort view but has a maximum occupancy of 3.

I contacted the hotel requesting an upgrade to a suite and their reply was:

>> please consider that the suites are not eligible for complementary upgrade
>> A paid upgrade is possible at the discounted rate of 100usd per night for executive suite.

I give Marriott a lot of business but I need the upgrade this time and don't really want to pay 500.
Is there any value in contacting a higher authority at the hotel (options limited since I arrive Saturday night)? Marriott Rewards ?

Since my entire stay is on points, couldn't I use points for upgrade?

thanks
MR PLT and Lifetime.