Hello,
While I'm in no way associated with Rollbit (I work for a different casino, so basically a competitor), I'd like to give my 2 cents since this case seems very familiar to a lot of ones we're dealing/dealt with aswell.
Casinos nowadays have very strong multi-account detection systems, won't get into what they actually are for obvious reasons, but lets say when a casino is certain that you're using multiple accounts, they're pretty damn accurate

.
While I feel that OP's situation could've brought a satisfying resolution on his end, if he came clean and listed his accounts, it's also probably the case where in general players use multiple accounts to abuse the system, like double-spending, arbitrage betting ( gets limited on one account, jumps on another), bonus abuse, etc etc.
Now onto the Curacao regulator, while the general feedback of players like OP is to say "these Curacao regulators do nothing", the fact is that a case brought upon the license provider always gets dealt with, and a casino is free to offer all evidence against the player, thus why most players don't actually go forward with this.
As for how complainants will not be winning a case in Curacao [master license holder], call me naive, and though I have no way to prove the otherwise, I still hope some cases are actually solved in favor of the players. There are complaints raised against Rollbit that they redirected to their licensor and we never heard back from the complainants.
There aren't too many cases in Curacao that had to be handled/solved in favour of the player by the licensor for the simple fact that 99% of the times when an user is not engaging in any dubious activities, casinos solve these situations with favorable outcomes for the players themselves and there's no need to push things further.
My 2 cents on the matter,
Have a nice day!