Hello & Welcome to Just Answer,
Sorry to hear of any issue you are having with your phones.
To help you with this issue, may I ask:1) The Model Number of the MAIN BASE UNIT of the phone system you are working with? That should be printed on a sticker on the bottom or back of the main base unit and START with KX-TG (but have no "A").2) How many TOTAL cordless handsets do you have with this system?3) What phone service provider (phone company) you have for this phone line?4) Can you call from an outside line (cell phone, neighbor's phone, etc.) and tell me the number of rings BEFORE that "mailbox setup" announcement comes on?