Caller left no message so obviously just random call and not about anything. So I save the number, give it the name zpest, so all the zpests are at the end of my real contacts ....... then I press done (up at the top), go down again and press 'Block this Caller' (which is in blue) then press "Block Contact' (which is in red). This works, all the pests are called zpest so I don't have to see their names again and I do not hear from them again.

No message left so not a real call. Didn't recognise this number so googled it. Thanks for all previous comments. I like Rubbish deletion co - they have read my comments before and agree!! Do it. It works. I always say:
So I save the number, give it the name zpest, so all the zpests are at the end of my real contacts. Next I press done (up at the top), go down again and press 'Block this Caller' (which is in blue) then press "Block Contact' (which is in red). This works, all the pests are called zpest so I don't have to see their names again and I do not hear from them again.