Your Purchase Cannot be Completed

Dear iTunes Support Team,

I hope you having a great end of the week and I hope you will be able to offer insight into this for me.

Whenever I try paying with a card (completely working, money available and everything, not blocked or anything) in a game I get the error message of 'Your Purchase Cannot be Completed' whenever I try purchasing some in-app stuff. What can I do to resolve this?

I am kindly looking forward to your reply and wish you a lovely weekend ahead.

Thanks in advance,

Neptune