For something simple it shouldn't take more than 3 months. I had issues where it took just 1 week for example, and more than take the casino is stalling to keep the money.
You are right, even in less than 1 hour the case can be resolved but if the case is related to match fixing then it will take months because of the lack of evidence well here we don't know what the problem. In such a situation, the admin should continue to provide updates regarding the case so that users are not confused yeah at least he can monitor the progress or maybe this is their way of keeping quiet so that users forget about the case
Come on this is the right time to change the service mode to get a good reputation.