What exact rule did I violate?
Based on their tone, it appears they believe you have had multiple accounts with them before. What we need to know is that did you user shared devices or even public Wi-Fi when registering or logging into the casino before?
Eventually they have to tell you why they blocked you.
What evidence do you have for these accusations?
1. You haven't shared evidence either. Just an accusation with no proof
2. They are most likely not going to share the evidence here. Try independent arbitrators like Askgamblers -
https://www.askgamblers.com/online-casinos/reviews/betcoin-casino/complaintsIf a Betcoin.ag representative is reading this, feel free to explain publicly what exactly I did wrong.
This is likely not going to happen.