Same thing happened to me. Some guy is sending messages to everyone on my contact list as well as other random people who are calling me now, asking who I am and why I'm sending them messages. Tried emailing whatsapp.. It's been a week and no reply. This guy is making me look like an idiot because my name and number appears on random peoples phones now! Please let me know if you find anything out!!
but uninstalling @whatsapp wount solve the problem.
that guy could reinstall the app from playstore as he owns the sim card and phone.
should not whatsapp include a passkey to access it like cubie does?