I got an error code 2 when I was paying for the premium course, what can I do?

‘Error#2’ is a common error code for the Authorize.net payment gateway. It means the card has been declined, either due to lack of funds or the card-issuing bank has blocked the transaction. 

If you have available funds, contact your credit/debit card issuers bank and check if the fraud department is blocking the transaction due to an unfamiliar online sale.  This issue is usually cleared up quickly.