I went through the same thing OP... accidentally apped for the PRG without knowing you can't after a fresh denial.
I called the Rep they told me 10 days not 30 days and gave me an actual date I can apply again on.
The only language I found anywhere on the site said 30 days so I was skeptical but sure enough I apped on the day he told me and was approved for the PRG. I'd call them and see what day they actually have in the system for you to become eligible again.
Here is my thread if you're interested.
https://ficoforums.myfico.com/t5/Credit-Card-Approvals/Amex-PRG-Disappeared-off-Website-Update-Appro...
