How to delete an iPhone contact completely?

I have deleted a contact in the Contact App. However, when I'm in the SMS app, the contact (name and number) still appear. I want to get rid of the contact for good. Any help, here? There are no text messages from that contact on my phone. Incredibly frustrating…

Too long for copy and paste:

http://10network.justk2.com/2011/07/how-to-completely-remove-contacts-on.html