Verification code sent to an old phone number

I have a registered learner who is unable to access their account. They are prompted to enter a verification code that is being sent to an old phone number they no longer have access to. They select "Get Your Code Another Way" and a verification code is sent to their email. When they enter the code from their email they are then prompted to enter another verification code that is sent to their old phone number. How can they access their account and/or change their phone number without being able to login into their account?