cant buy java edition because there is a bug

when I put in all of my gift card info (I'm pretty sure it does it with normal card info too I have seen videos on youtube.) and hit "purchase for 26.95" it comes up with a message saying "an error has occurred while placing order, please verify payment info and try again." and I have tried multiple times over and some videos have a way to fix the problem but it doesn't work for me for the ones I have tried, I will keep trying and hopefully get it to work...