Hello, I'm having some issues with my bank card. It seems like I can't use it to purchase cryptocurrency. I've tried several times, but the transactions are always being declined. Could you please help me understand why this is happening? I've checked with my bank, and they say there's nothing wrong with my card. Could it be something to do with the crypto exchange I'm using? Or could it be a problem with my bank's policies regarding cryptocurrency transactions? I'm just looking for some clarity on this matter. Thank you.