I got this from help center bot:
If your account access has been deactivated, it’s likely due to a violation of our content policy or terms of use.
If you believe this happened in error, please reach out to support@openai.com with the subject line: “Deactivated User Appeal”, and include a justification for why your account should be reactivated.
Just sent the mail several hours ago without receiving any reply yet. You can try your luck.
ps- Link to the post shows how to activate help bot in help center here: My ChatGPT account was deactivated - #11 by linus