This is a clear failure of their responsible gambling policies and a breach of their duty of care. A self-exclusion is supposed to prevent this exact situation. I am now seeking a full refund.
Based on what AHOYBRAUSE posted, it seems like you are looking exactly for this kind of situation. I mean, you go gamble in casinos, request self-exclusion, create another account in the same casino, gamble, and when you lose, you claim something like this and demand a refund.
I am also curious about what Zwei said. When did you do the KYC verification on the same account? Was it before or after you lost?