Well if you feel that you have been scam by that website, I suggest to bring this thread to the scam accusation section, not here on the gambling section.
If there was someone reported about the same bugs, OP should not be able to find it because professional casino will fix it as soon as possible or at least deactivate the related features which may make them lose some money. I see that the bugs reported by OP has big possibility to be abused and may make the casino lose a lot of money. I think the casino should at least give at least a "thank" for OP to report the bugs. It does not matter the bug is reported already or not, but I think rewarding people who found bugs in the casino is a must. It does not need to be in a big amount of money but it can be anything as appreciation from the casino to anyone who reported the bug.
They should at least give proof that the bug was reported earlier by another bug bounty hunter and not just say that they know the bug and working on it already, bug bounty hunters will just suspect that they want to take advantage and do not want to pay, a mere thank you is not enough, I don't know much about coding, but based on what I read it consumes time and too much effort just to find bugs.
OP mentioned that he is not expecting big rewards so Betfury should get a hint and reward OP on what they think he deserves, and casinos should create a page or announcement about bugs for transparency purposes, so in case one bug bounty hunter finds one bug he can check the page if there's already a report on the bug.