Can't buy aimware: paypal tells me to use a bank account

Hello!

I wanted to buy your cheat for Christmas, but when trying to process the payment on paypal, it tells me

Vous ne pouvez pas utiliser cette carte bancaire pour cette transaction. Veuillez utiliser une autre source d'approvisionnement.
(translated into english: You can't use this credit card for this transaction. Please use another supplying source.)

I don't understand why it doesn't work, and I don't want to add my bank account on paypal (i'm not crazy).

Any idea why it does that?