Payment method - Crossfire BR

Good afternoon, I'm trying to buy the cheat "one month", and the card is refused, I'm from Brazil, and my card accepts international purchases and has the balance to make the purchase. The method used is Stripe, how can I solve it?

Is there any other way I can buy the cheat via credit card? for example "Mercado Pago"?

You can try by one of our resellers including myself.
More likely your card is blocked by your card provider for online payments.
For the first instance, I would speak with card provider to make sure they allow you pay online by that card and in other countries too.