If your message has been delivered to the recipient, then you're unlucky, because the message that you typed has been already delivered to the recipient, hence it is impossible to recall it from the recipient mobile device in WhatsApp.
A WhatsApp message can only be recalled in any one of the two scenarios
1 When you have send the message and the clock check mark pops up.
At this stage the message that you have typed and sent is not yet gone to the second stage (i.e. it has not yet moved from your device). Hence deleting the message from your device at this stage will prevent the message from delivering to the recipient.
2 When you send a message and only one tick check mark is visible.
The message that persists in your device after the one tick check mark is just a copy of your message that you have sent to the recipient, the actual message has already been sent to the WhatsApp server and will be delivered to the appropriate recipient once he/she switch on WhatsApp on his/ her mobile. However, since the message has not yet reached the recipient mobile device, blocking the message from the WhatsApp server itself will obviously block it from delivering to the recipient mobile device. You can do this by blocking the contact immediately on WhatsApp. Keeping them blocked for 30 days (or) till they switch on WhatsApp on their mobile device will automatically block the message from delivering into their account.
If the recipient opens his WhatsApp Account while it's still blocked by you, then your message will never/ever be delivered to him even if you unblock him later on.
Caution : Unblocking the recipient before he opens his Whatsapp account (or) before 30 days will deliver the message sent to the recipient.
Note: Undelivered WhatsApp messages will be automatically deleted after 30 days from WhatsApp server(i.e: If you send a message on WhatsApp for a contact if the recipient is unavailable and not switched on WhatsApp in their device for the past 30 days, then the message will be automatically cleared from the WhatsApp server, hence it will not reach the recipient account).
Don't have the patience to wait for a 30 days period, then once you know the contact has opened his WhatsApp profile through their last seen notification, then Unblock the contact on WhatsApp, and conclude that your wrong message wasn't delivered.