Well mainly, it proves the card is yours and in your possession. If you haven't used the card at the casino then they wouldn't ask for it, just cover some of the numbers before you send it
I don't understand the logic. Why does it matter if I have the card or not? I'm still withdrawing to the card. If I don't have it, why would withdrawing to it matter? I do have the card of course, I just feel like the casino is being difficult for no reason. Before I even began playing I sent all my docs so I can withdraw when/if I get the chance, and I was supposed to be good and now they throw this at me.
The casino in question is Novibet. They have a rep here, but mind you that since posting the competition they've not returned nor have they responded to my PM that is now over 1 month old (different issue).