Cannot upgrade account due to an error while processing card

I want to upgrade my account from free to hacker. I entered the card details but an error message popped up saying "An error occurred while processing your card. Try again in a little bit. " I tried once in a while but the same error occured. My card is a Mastercard debit.

Hi, It seems like you were able to upgrade after you posted this message? Do let us know if you are still seeing any problems.