On one hand, I'm aware that people do these things. They contact a casino with a request to be self excluded and if the casino doesn't do it well enough, for instance blocks the account but not the IP and allows the user to create another account and lose money, the user then asks for a refund and threatens to post it on forums.

On the other hand, they did not block the account at all, but also told the player to wait for them to message back and never did. The player did not remind them about it and deposited money knowing that the exclusion was not handled well.

I don't know. Fells like both sides are at fault here. I wouldn't use 1xbit due to accusations, but it doesn't look like it's 100% their fault.