Don't be alarmed?!
Who the hell starts a phone call by saying that?
How about...
Don't hang up on me, I clearly have no idea how to talk to people via phone calls...

That would have been the more appropriate line for these people.

It was just an automated phone message
but
c'mon get it together!
If you don't want people(like me) to hang up on you, you have to come up with a better opening line.