Unhappy [Q] Help me delete this contact!

It's somebody who I added to my circles on G+. I had to reset my phone because of some prob, but forgot to take contact backup. When I reinstalled WhatsApp! I was still in all the previous groups, but the only contact I had was this person. So I ran to my contacts to hide all my GMail and G+ contacts but I found this person listed under WhatsApp! contact. So I removed the person from my circles (the person is not in my GMail) and now the person is no longer in the WhatsApp! contact list but they are still listed under WhatsApp! contacts in my Phonebook. I can't edit the contact at all. I really want to delete this contact help!