This is from the team at GoGetFunding whom I communicated with in regards to some problems with donation paymens. They advised; 'If donating via card fails the first time, they will see a button to click to make a donation via Stripe (your back up card handler). For US, Australian and Canadian donors, their banks seems to prefer this payment handler, so ask them to try this if their first attempt fails.

Alternatively, you have a PayPal premier account which may accept card donations from donors who do not even have a PayPal account - they would need to click on the PayPal button during the donation process and when they get to the PayPal summary page click on 'pay by credit or debit card' instead of the option to 'log into PayPal account'.