Computers screw up.
computers programs can screw up, but in this case that seems unlikely to me
what I imagine happened was butlerblockhead refreshed some page that he shouldn't have. chrome at least (but I'm sure most browsers) warns you when you try to refresh a page that involved a POST request, but it wouldn't be hard to believe that he just ignored the warning, if that's what happened
If a company charges you for something you did not purchase and refuse to refund it they have committed a crime.
no they did not...
first of all, the company doesn't have any responsibility for your browser messing something up. that's all on you, and the software you're using
and second, in the case that your browser messed up, they probably don't even have any way to tell on their end. to them, it just looks like two perfectly legitimate purchases for the same keyboard. the only thing they'd have to go by in that case is your word, which they don't have any obligation to trust over their computers