Found good flights but can't book them
I found Aeroflot flights from IAD to BEG via SVO. Tried to book them online but my credit card was not accepted. I cleared cookies, used a different card, and used a different browser, but none of these helped. I called Customer Care at 866-879-7647 and gave the CSR my reservation code. He found the reservation and asked me to enter the credit card number over the phone. But that also did not work.
What else can I do?