Someone is hacking my email

Someone is hacking my email, and there is no contact details to cpntact gmail about this situation. I can see that this person is on my email, with recent activity, gmail tracks the tablet to only South africa, there is LOTS of people in south africa. i have tried to sign out of all other sessions, and changed my passwords etc, and it still doesnt work.. I NEED HELP ON THIS.. please i cant take this anymore...