Hi there.
How about this: try to request your gaming history associated with the game, add your printscreen, and then send it to the game provider who created the game with an explanation plus a demand for an inquiry. The point is to get your logs checked by the game provider itself.
I mean, if you are 100% sure there was something abnormal in the game, only the game provider may confirm that.
The fact that the casino is willing to compensate you truly supports your point of view.
Another step is submitting the aforementioned complaint through our Resolution Center. Maybe this game provider's inquiry would also be addressed.
I think both ways are worth a try. Still, I would prefer the complaint here (use this link to begin) because, throughout the whole process, you'll have your own complaint handler on your side to assist you and guide you through.
I bet it sounds more convenient. 🙂