we purchased an att answering system/phones model # EL52300. The handset shows that we have missed calls but we cannot identify those phone numbers. Only instructions in our manual is how to delete the notice that we missed those calls. In addition, we have lost the factory message for those people to leave a message. The phone will ring about 7 times and the a recording asks to provide a code? We have not found how to set up our own message and to receive messages. Joe Voss 480-671-5191