Any casino may experience the same thing like this including the one which is on your signature, not all cases can be resolved quickly as what players want because there might be some further verification need to be done by the casino which may take longer time.
Maybe I should say that almost all casinos must have experienced complaints from players, when it comes to solving problems then it depends on the team that handles with their security department.
Of course I have to agree that how the casino respond to complaint is important but once the casino ask players to wait, players cant do nothing except waiting.
I know waiting for unknown time can be frustrating for players (including me if I experience it) but keep on asking the casino multiple times while they have said to wait will not help the case to be solved faster.
Maybe by asking to wait from the casino, it is possible that the casino is waiting for news from the provider about the related problem, so it may be that the casino cannot give a definite answer if a statement has not been issued from the provider.
I hope Shuffle will come here to clarify about the recent complaint(s) so we wont speculate too much.
I see the @Shuffle team has been active recently, maybe they are looking into what happened and will clarify soon.