Well, that gets us back to the beginning. There is no problem with the casino proofs.
Throughout my explanation, I have emphasized that based on your activity, we had no evidence to disprove the casino's accusations. ??
"The use of multiple accounts on the same device suggests the utilization of multiple accounts by a single individual and it would be impossible to prove that it's not just one person playing in both accounts."
The rejection of the complaint stemmed solely from this issue. We could not back your story up. Nothing else played any role.
Hence comes my previous comment:
"I believe it was an honest mistake. I mean, never allow anyone to register a casino account from your device; it is a mistake. If you browse casino rules, it, in my opinion, becomes obvious that doing so will only bring problems. Why would the terms otherwise explain the KYC and fraud measures involving IP, for example? You may find it hard to defend such a step if we are talking about an online casino, not a brick-and-mortar one. I'm honestly sorry."