What was happening to me is they would call. I'd be driving and by the time I could get my stupid Bluetooth headset on, it would stop ringing and go to voice mail. I couldn't just call them back because I wouldn't know which asshole it was who called, so I'd have to check the voice mail,
"You have reached your Verizon voice mail box. Press 1 for English, (pause for 14 seconds) . You have (long pause) one (pause) new voice message (long pause) To listen to your voice messages, press one (pause) first new voice message (pause) received today (pause) June 7th, two thousand (pause) eight (pause) at (pause) eleven (pause) forty three (pause) AM (long pause) begin message:" - This Dale call me back" (long pause) "End new messages. (pause) To replay this message, press one (pause) to delete this message, press two"
All that hassle just to find out which one of those bastards called so I know which extension to dial when I call them back.
I was at a Verizon store once and asked if they could turn off the voice mail. Dude said I can't, but I can just quit checking it until it's full.