Locked out of account

My mother received a notice her account was locked for safety.   She has reached out to cox several times via phone and spent several hours on the phone and the local store and everyone tells her they are unable to help her.   They tell her they are unable to text her a reset code because her phone number is associated with her account, which seems totally backwards.   They also tell her there is no other way to reset and reclaim the account.  Someone from an office in Las Vegas told her to go to the local Cox store and have the store call him and he would be able to assist once they confirmed her identity, but the store tells her they cannot provide any tech support only sales.  Please help, as this is her only email account and is the access point for almsot everything in her life (utilities, banks, etc.).  She was finally sent a temporary password which let her in one time but now she is locked out again and cannot get anyone to help send her a password again.