If they didn't receive your money until after betting was closed, then you didn't purchase anything. Whatever is written in the rules can't take away your consumer rights. If they don't provide the service paid for or send a refund it's just theft. There not protecting anyone by keeping the money, just lining there pockets.
The service is GAMBLING. GAMBLING is risky. When bets are time average weighted you
must discourage late bets. Why?
Masses of idiots like you would spam the blockchain at the last possible second when the bet outcome is known, for even a 1% winnings. This screws early bettors and creates 95% of the work for bitbet admins for 5% of the customers. The same 5% of childish people that bitbet is discouraging, because they are the worst kind of customers.
This OPEN discouragement of late betting is clearly explained as such, in the faq.
You're telling me you went and sent 10btc, at the time, ~$8,000, without even reading the faq? And you're blaming others for this oversight?