1. This is not a Bitcoin technical problem. Is a gambling problem.
2. How on earth you gambled off 6.5 BTC?! What was in your mind?!
3. If you would have won an extra 6.5 BTC, would you have offered to give it back to freebitco? Then why you expect to get your money back?!

Gambling sites are not charity and the main rule of gambling is always play only what you afford to lose.