Locked out/son passed away

I cannot. The questionnaire locked me out.

I do not know gaming, or pretend to.

Do not bill my son for XBox Live etc. while he is locked out.

Depending on how you (or your son) set up your son's accont, and if your son is still a minor, the son has to be added to an adult account.

Have your own adult accont and sign in on
https://account.microsoft.com/family and add your son's account to your family account.

Then go to
https://account.xbox.com/settings and restrict his online and privacy settings to your liking. You can also enforce game time limits.

But the most practical approach would be to lock away his controller or taking away the power cord of the console.

Hello, if you feel there was an error you can contact the enforcement team and file a case review.

https://enforcement.xbox.com/en-US/Home/HowTo#sub-topic0-6

He could have caused an infraction days before the suspension was issued. They are usually given out for poor behavior over xbox live. The xbox team will have investigated any claims against your son's etiquette and sent the ban.

If you go to enforcement.xbox.com you can start appeals processes there. Please be advised that it can often be the case that suspensions are issued weeks after the infraction has taken place & the reality is that enforcement action is never taken without
investigation.