Deleted iPhone contacts still there?

I deleted contacts directly from the "contacts" section of my iPhone, however, when I use apps like GroupMe or WhatsApp, the deleted contacts still show up in my "contacts" tab in the app. Also when I compose a new text message, if I type the deleted person's name in the "To:" section, their name and number still pops up. Any idea how to permanently delete someone's number off of your phone so this won't happen?

No way, iphone did not have the facility of deleted file.