Q: Payment method declined while trying to download a free app?

I have previously used my mastercard to buy an app on the app store. Now a few weeks later i tried to download a free app but it keeps asking me to verify my payment method. I fill in my all my card details 100% correct and it says it was declined and i need to enter another payment method. This is pretty weird concidering that i'm trying to download a free app.

Thanks in advance,

Lex Magnus