Gmail account stolen

Hello,
My gmail address has been stolen. Early October 2016 gmail didn't accept my password. On password recovery page the telephone number to be used to text or call to assist in password recovery ended in numbers which have never been part of my telephone number. The authentication code sent to my non-gmail account was insufficient to "recognize/authenticate" me as the me who created the account several years ago, so I still do not have access to the account.