i can’t get my old account

hi i’m from south africa and i came to the US on holiday and i bought a new console.the series X i used to have an Xbox one x. so i keep trying to sign in on the new one but i can’t because im unable to get the security code because it sends to my old number that i have no access to. i’ve tried recovering my account but i keep getting told they can’t verify it. so what should h do? please help me

:)