Question :GMAC's rule of maximum 8 attempts (specific to my situation)

Hello,

I understand that the GMAC notified about the rule for maximum 8 attempts on June 19, 2015 and the rule came in effect from Dec 17, 2016.

My situation:
I made 4 attempts prior to the GMAC's notification date (June 19, 2015) and 4 attempts after this date.
Due to some reasons, I was unable to get the desired score.

Upon trying to register, the GMAC website didn't allow me to register for the 9th attempt, and upon contacting the GMAC they suggested me to send a petition with any supporting documents.

My questions:
(1) Given that there was no way I knew about this rule prior to June 2015, I should logically be eligible to make 4 more attempts.

Is there any precedence about the similar situation with someone else, and what was the GMAC's decision on that?

(2) Could someone guide me about the format of such appeal (to make the 9th attempt) that I am advised to send to the GMAC?
Which documents could someone attach with such petition?

It would really help me to know about these and get connected to someone who has gone through the similar situation.

Thanks for taking time to read it.