HOW TO BLOCK UNKNOWN CONTACTS
--Open your whatsapp , tap on the MENU which is the three dotted icon located at the top right corner of your phone screen
--Tap on SETTING ,
--Next select ACCOUNT
--Then PRIVACY and select
--Tap on the contact icon to select the contacts you wish to block
With this simple steps, the selected contact have automatically been blocked.
--First Open your whatsapp,
--Open a chat with the contact and tap MENU which is the three dotted lines on the top right of your contact page
--Tap MORE , select BLOCK; three options will display on the page requesting if you would want to
BLOCK, CANCEL, REPORT and
--When you block a contact, the messages, calls sent by that contact won't be delivered to you.
--Your last seen and when online won't be visible to them.
--When you block a contact, your phone number won’t remove from their contact list neither would theirs be removed from your contact list, except you delete it.