Try starting your browser in safe mode. You might have a rogue add-on installed.
If that works, call your credit card company and ask for a new card number. Tell them you might've been hacked and your info stolen, they'll change it for free. Also disinfect your browser.
Well I didn't actually enter any card information, seeing as it was obviously the wrong place in which to enter said information.
Well, that's smart of you. Good sense.
But still, if a web page containing the words "credit card" is behaving oddly, your browser may well have malware installed. Seriously, at least check it out. It'll take you just two minutes to do a safe-mode browser test.
(With Firefox, you do have to shut down your current session. Stupid of them.)Maybe I'm being too suspicious here... I hope so.
I just did a run test to see whether or not I could buy the game easily on minecraft.net. And it was weird...
I had to login on minecraft.net (the login link at the top-right), and not directly in the store, and without checking "remember me", and then it worked and I could buy the game...
I can't speak to this. I bought through the website, but it was years ago, back when Alpha was ending.
It's hard for me to believe that their website really works so weirdly, but then I remember that Mojang doesn't really have their act together. Things just are not seamless.