Hello from Argentina!

I´ve been paying my subscrption with my credit card but (for personal reasons) wont be using it anymore.
So I decided to buy a Time Card(60 days) from a store here in Argentina, but the guy who sells them told me that they only have "american" cards.

When I choosed my country and region in the Mog Station account I put Argetina(country) and The Americas(region), so I dont know if I should buy the time card.

Will I be able to redeem the Time card even if my Mog Station account is from Argentina?

I looked upon the internet but I couldnt find an awnser, and the guy from the store couldnt tell me if it will work( he should know right? )

NOTE: Im playing in NA servers( I dont know if that really matters)