How to recover a stolen Apple Account with changed mobile number?

Read this document if you think your Apple Account has been compromised. --> https://support.apple.com/HT204145

I could post a lot about getting a OTP using other methods but since you say your account has been "stolen" and Apple has told you there is nothing they can do to help you recover the account that then it is probably true.

Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Read the requirements and steps for an Activation Lock support request at: https://al-support.apple.com/#/additional-support and links at the bottom right for the type of service requested. Apple says they “may” require "proof of purchase documentation” and that you need “proof of ownership documentation”, but does not detail what currently constitutes proof other than it “must include the product serial number, IMEI or MEID.” User reports on this community indicate that typically Apple will absolutely require, and ONLY accept, an original receipt issued by Apple or an Apple Authorized Reseller. Presumably this is the only kind Apple can authenticate against fraud since Apple is not involved in third party sales. Apple recommends that you "Keep your receipt after you buy an Apple device" --> https://support.apple.com/HT202711

Note that the device cannot have Lost Mode set on it. If the account thief has set that too then your equipment use is lost to you.

Hanny333 wrote:

A month or so ago I got an email out of the blue saying that I have enabled Two-factor authentication - and that if it wasn't me then to click on the link

I thought it was a scam link so didn't follow it up

I'm not sure how they managed to log in

They logged in because you did not have two-factor authentication enabled, and they then took steps to protect and secure the account against take-overs by others. Including a re-takeover by you, most likely. The password or maybe the security questions were guessed, or the password was re-used and leaked, if this follows a common pattern. This account will never be coming back to you, again if this follows a common pattern.

Hi. I've had to create this (my wife's) account as mine has been stolen. They have changed the accounts mobile number, so I don't receive Two-factor authentication OTP when I try and log in

I contacted Apple support here in Australia, and they told me that there is absolutely nothing they can do to recover my account or change the mobile number back

I find this difficult to believe - hence my post to see if this is true?

It is true. Assuming they have already changed the password, they own the account now.

That Apple Account is gone.

Reusing passwords can be one cause (and if that reuse happened here, then other uses of that same password are at risk), while enabling two-factor authentication can help mark compromises more difficult.

How did they manage to change the number? In order to do that they would have to have the account ID and password and a trusted device or trusted telephone number. The whole system these days is designed so that people can't just use your password and user ID to make changes to an account.