Ok this is the part that makes me KNOW that NANO is in the wrong.
This is a direct quote from their terms of service pages as seen here
https://nanogames.io/help/agreement.
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"6.2. We have the right to remove the chat room functionality or immediately terminate your Member Account
and refund your account balance if you:(a) make any statements that are sexually explicit or grossly offensive, including expressions of bigotry, racism, hatred or profanity;
(b) make statements that are abusive, defamatory or harassing or insulting"
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The list of reasons continues for a while but they say it there themselves.
They will refund account balance to those who are removed because of chat rule violations. The reasons they gave other than the broken chat rule were all determined to be forgiven when they previously let him back into his account.
If this goes according to their own posted rules and terms they are supposed to return his balance, not just his deposit. Otherwise, they should have to return all his deposits from the date of the first (resolved) infractions. That might be a bit more expensive than the winnings so it would be smart to just give the guy his money.
They owe him that money.
Period.
Here is a screen shot of their written terms about chat violations:

Regardless of how they feel about this man, they should return the funds that HE WON after being a long time player there. It is beyond messed up that they banned him for old stuff only after he won.