The bonus was 1 per user an you tried to scam for many Bitcoin.
The terms for the bonus were very unclear:
Bonus terms:
[...]
Bonus can only be claimed once
[...]
Is that once per account? Or once per person? Or once per computer? Or once per household? Or once per IP address? Or something else?
You said "bonus can only be claimed once", and despite me asking twice for clarification as to what that was meant to mean you never provided the requested clarification.
I think the most obvious interpretation would be "once per account", since the site wouldn't let me claim twice on the same account, but would let me claim twice on the same computer, from the same household. I don't think it's fair to withhold funds from players who misinterpreted your incredibly vague terms.
It's also very rude of you to call this player a scammer. He wasn't scamming you. He was playing within the stated rules. If you offer stupid exploitable bonuses please don't blame anyone but yourself when people inevitably try to exploit them. Promising a bonus and then refusing to pay it makes you the scammer, not the people trying to claim the bonus.
Absolutely. This is why I'm always wary of +EV promotions that casinos give to the players because
is to see players' accounts being flagged for arbitrary reasons ("abusing the promotion"). Hey, I've got a great idea... don't offer a promotion and you won't get abused!