I never used CoinRoyale website so far, I don't think they are active in Bitcointalk forum, and I can't find if they have any betting license, if that is the case don't be surprised that something like this happened.
You should read terms on their website and if they have some rule that can terminate your acount for being dormant for years than there is nothing you can do about it, and there is nobody to complain about your problem.

Actually being dormant account for too long would usually be having this kind of problem since most website or platforms would definitely be wiping it out
or freeing up some space but the thing here is that they dont make out such response when you are still actively sending out some email to them
in regards with the issue.Im dont experience on playing with Coinroyale though but talking about chances on getting those funds back or
account to be accessible again is very less likely to happen.