From what I've seen of the reviews of Nitrobetting casino, most of them are completely dissatisfied and unhappy with their experience with this casino due to the extremely long delayed payouts and various issues they faced. There are also those who are still waiting to receive their money after much longer than expected. Also, their forum account [
this one] has negative trust ratings and has been inactive for a long time, which clearly shows they have no interest in their players, nor any willingness to cooperate or protect their reputation.
Unfortunately, there is no one on the forum to assist you regarding this bad casino. You should file your complaint on other review platforms or on platforms that act as a mediator between you and the casino in the hope that they will respond. Follow what @acroman08 suggested.