Why can't I get Minecraft?

Every time I enter my credit card information it just goes back to the page I was on and unfills all my credit card numbers, without even telling me the purchase is complete, why can't I get Minecraft?

Try doing it again. You must be doing something wrong. Have you already paid for the game?

It's probably not minecraft, it might be small faults on your computer, it did that when I was making a YouTube channel apart from I was filling in my information