My account has been banned and I don't know why?

Afternoon all,

Came home after a short holiday last week to find my account banned. No idea why. I don't bot, I don't cheat, and I only chat when making a trade. 20+ years of single play and then this...

I responded to the ban by contacting Blizzard, asking what had happened and why, because I hadn't done anything, and got a generic "breach of terms and conditions" email. Ban was upheld.

I appealed this to Blizzard, wanting to know the specifics of what had transpired as I had absolutely no knowledge of what had set off the alarm at Blizzard HQ. Got a response from them and I got the following, and I quote...

"Game Master Thuinnar here.

Your Diablo 2 Resurrected game account has been permanently closed due to a violation of the Code of Conduct.

After thoroughly investigating the situation, I concluded, based on the evidence we've collected directly from your account and its activity, that the action was appropriate, so it will not be overturned.

We are unable to reveal any additional details outside what's already been disclosed in the original email that was sent alongside the account action (check spam and trash). You may submit a data request to obtain additional information.
- Want a Copy of my Data: https://support.blizzard.com/article/000157641

This action is in accordance to the Diablo 2 Resurrected game Policies, which were acknowledged and accepted by all players before they could start playing the game. These policies and conditions allow us to keep a safe and fun environment for all players. We recommend that you review the links below for additional information on the Code of Conduct and Terms of Use.
- Code of Conduct: https://battle.net/support/article/42673
- Battle.net Terms of Use: https://blizzard.com/company/legal/eula.html

Please note that, because we have reviewed our actions and verified them to be correct, we consider this matter closed"

And that's that. I have no idea why I would be banned, and no specifics were supplied so at very least I would know what they were on about. I am literally at a loss, to think 2 decades of play has led to this. I'm damn sure I wasn't hacked, and I know I didn't do anything, so is that it?

Had this sort of thing happened before to anyone else?

I'm really just stunned at the circumstances, and the manner in which Blizzard has shut me down without answering my simple request as to what I am allegedly supposed to have done. Because I certainly didn't.

Apologies for the rant, but can anybody add anything that may be helpful?