Lost iPhone

Hi Guys,

I need help here. I was robbed and my iPhone was gone as the theft away. I had activated the lost mode through iCloud. What I noticed, later on, the bypass the phone to reset the apple ID password through my email. by that, I have managed to alter all of the account passwords that I have. I changed the apple ID password and check in "Device" that the phone was under my account. Suddenly, it was gone! I did not remove the phone but its gone. I have checked the iCloud as well but, the phone still under my account.

What should I do then? I don't know how to contact apple support about this issue.

Thank you guys...