The THB 999 rate does work, i have used it at the Courtyard in Surin and was able to make a reservation at the Courtyard Patong as well. Given the low occupancy in thailand right now, my guess is that the rate can still be booked without problems. During local events, like Songkran or Chinese New Year availability might be limited however.

Unfortunately it seems that the JW Marriott Phuket has finally started to implement some "enhancements" and showing signs of "unwillingness". As i am pretty sure that you are lost once you are at the resort i would try to get a reservation before going there. I would suggest trying to contact the gold card office at the JW Bangkok again, or, if staying in Bangkok before, visiting the JW in person. I had good experiences doing all my gold card reservations together with the front desk at the executive lounge there also. Instead of paying the the regular rate for a suite i would also suggest taking a look at the rates for the 2bdr units at the MVCI Beach Club or the new Mai Khao Beach Club. The latter one should be not that expensive if booked via one of the preview packages which are on offer by the local MVCI sales team. Asking for a stay at the Beach Club instead of the Mai Khao units might be approved as well.