DHL contacted me on WhatsApp and wants me to send them money

Sorry for the clickbaity title, I'm in a rural area and don't receive post, I recently got a package sent to me internationally via DHL (you can imagine the occasion). There are customs duties to pay, but DHL's payment page is broken, confirmed by a friend spending 1 hour on the phone with them. Then a couple of days later I get a WhatsApp message (we don't have mobile service here, but we do have internet) saying I should transfer the import tax payment to an account and they sent me a photograph of the account on a piece of paper. Questions: is this normal, should I pay, and how can this the level of security that DHL, probably the biggest postal company in the world, employs?

Nope, that's a scam. Do not send money to that account. Contact DHL customer support directly using the number from their web site. This is a common scam.