Hi , mi name is Pedro , from Chile ,i instlled the version of avast premier 2015 trial for one month , but now , i wish purchase this ,with the offer , but i not got visa or other cards international , only credit card of Chile .
i see in the page , appears only ,visa ,mastercard and other , but i cant purchase , thanks for yours help ( i speak spanish and not use translator ) 
you could try a reseller in Chile
Is there not an option to pay with PayPal?
It takes a little while however you could transfer $$ from your account to a paypal account and pay that way.