I got it to work by selecting the credit/debit card check box and re-input all the info.
Originally when I tried with my saved debit card I was getting the error. So input my credit card info and it worked first time, immediately got my coins in game. I go into my bank account today and see that I was charged 3 times on my debit card that gets the error, but I still have not received any coins for that.
Hey, when I go to buy coins (and obviously fail), I tried clicking on credit/debit cards, entered all info again (instead of the saved 'visa' option on top) however it's saying my card number isn't unique to this user ... do I have to somehow delete the saved info it has of my visa?