I can't make payment to certain merchant

[jerrybe]

I can make payment to all the merchant except for one. It says my card was declined. However, I still can use that same card buying in other sites and real stores. It shouldn't be a problem of my card.  In fact, I have made purchase before in that site with which my card is declined now. Why my card got declined just in certain site? How can I fix this?  

[kernowlass]

@jerrybe

Maybe they don't sell to your country or maybe they don't accept credit cards.

Failing that ask your card issuer why they declined the payment?