Can you provide a screenshot of the mail/chat? You can upload the image to imgbb or imgur then post the direct link here. I feel like casinos become so secretive when it comes to penalize their users which is really unfair. Soon as they told you were cheating or whatever then that's it, no more reason needed lmao. What a mess, this kind of casino should be boycot here regardless hoe reputed they are in the past.
Okay, I'll try to get through to them at the post office and provide a screenshot from the mail, if not, then from the live chat
Before anything else drop your username or account id so that if they are following this thread they can trace the username and account id you provided they have resolved one issue already, and you may send a message to their representative, I believe this is his account
https://bitcointalk.org/index.php?action=profile;u=2912800.
Your issue is the same as the one they just recently resolve although both of you deny the accusations maybe its time for a third party to mediate on these concerns because they keep flagging those who won big amounts which is unfair, Duckdice should also post the message of the provider since its the provider that flagged the account.
Right now it's not recommended to play on Duckdice until they resolve all the issues here.