Xbox Account got Hacked and the person changed my back up Email and took my Phone Number off.

afew days ago i was in the middle of a game on my Xbox when out of no where it kicked me out of my profile and said i was signed in on another Xbox,

a few Mins later i get a Text from Microsoft saying my Phone Number and Back up Email has been taken off. well i go and get on my Computer and try to sign into my Account and it kept saying wrong password, well i was able to change my password since i knew
everything about my self.

as i look at my settings i see that my Recover Email was gone and Phone Number(i use my number as a recover also) and they were replaced with a Email address i have Never had or seen before. i click on
activity and that someone in Australia
was on my account, i Live in the U.S., i have never been outside the U.S., i have had my Xbox account for 10 years and never signed into my account out of the state i live in.

Now because this guy has his Email as the Recover Email, i can't change anything only my Password but then he goes and changes it again. i need help getting Full Custody of my Account
back. i try to call Xbox but the recording tells me to go online but that still does not Help. i don't why Microsoft would let this person changed my Stuff when they knew it was from another Country and i have Never signed into my Account from anywhere else
but my Home.

:)