Ringba may decline some personal credit cards, especially those from Europe, Central American, or South America. Many personal credit cards from this area use 3D Security (3DS system) that adds an additional link to the issuing bank. Ringba does not support 3DS credit cards.
To avoid this issue, you can use a business credit card instead. 3DS credit cards are primarily personal cards, so corporate cards will generally work.
If you cannot use a business credit card, you can perform a wire transfer. Contact Ringba Support for help setting up the wire transfer.