Hey there! Nice to meet you!
Just to confirm, since you mentioned this, "The contact form remains inaccessible for input." Are you unable to submit a ticket through Microsoft Rewards Support? https://rewards.bing.com/support
The only option is to contact Microsoft Rewards Support, as they are the only ones who are capable of investigating a rewards suspension.
However, if you are unable to submit a ticket due to the form being greyed out, I'm afraid the suspension may be permanent.
Thank you for your kindness and understanding.
Best regards,
Darhyl