You may be seeing the numeric keypad inside the WhatsApp app. It won't make the touch tones required when you get the call. Use your normal task switching method to switch to the Phone app, and maybe select dial pad. It's tricky, and may take a few t...
See my other post with the solution on how to do it using the telephone call. It was tricky but it worked. That option lets you try it every four or five minutes.
