ATT DSL Service subcontracted ISP provider with Yahoo Mail

My father who lives in Connecticut at 75 can not access his email because AT&T DSL service uses Yahoo Mail which is incapable of resetting a user id and password for there customers if they can not answer the security questions. They have no policy for exceptions, as in does the average 75 year remember the answers to there security questions if they did not understand they should consider commonly asked questions so they will remember in the future. Some how my fathers prodigy.net email address is now owned by SBC, AT&T sells DSL home service with email through Yahoo mail, both AT&T and Yahoo customer service can not reset his account password. I worked in mainframe and client/server IT organization such as division and professional services for two decades you would think they would have exceptions or at least an escalation process defined for security. The more I research, the more I see references to inability of help desk personnel to solve the problem.