I want a receipt for the payment taken from my visa card. Why am I finding this so hard?

Receipts are sent to your email address. It sometimes takes a couple of days to arrive, so if you just made an order, wait a couple of days and the receipt will probably show up. Otherwise the only option is the Purchase History as described in the support article from which you came, and there's no print mechanism so you would need to take a screen shot of the relevant page.

Regards.