Error shown while making payments online using credit card

Hello,
I am an old credit card user and I have never experienced a problem in making payments online. I have been using a trouble free click and buy system for quite some time now.
Recently, I came to know about the new credit card payment option. So, I changed to that. The payment option was successfully changed then and there, but today, when I was trying to enter my card details, I was met with an error.
I followed all the instructions properly to reactivate my character, but when I entered my card details, it took some time and then gave me the following error:

