If the accusation comes with no single proof, it is fine to ignore it but if it comes with some proofs, a casino should not ignore it although the casino is not doing something wrong.
That's how casino should do to show their professionalism in dealing with complaints, accusations, or something similar.
Customers first and all business must know this as well as put it on a top of their to-do things for serving customers.
In general, both business and customers must respect each other and treat each other well. Regarding to customers, they should not react emotionally, and be crudal agains any business, as such actions only escalating things quickly. We know "Business must treat customers first" but staffs are human and they can lose their controls anytime so customers must know it and have proper elegantly actions when contacting for support, whatsoever.
Ignoring accusation while it comes with some proof is not a good choice to do, so I hope in this case shuffle will come to answer the accusation.
Ignoring customer complaints, accusations is bad as it is harmful for a business reputation.