Cox Phone Upgrade Incompatible with Home Security System

I keep getting letters about the phone upgrade and I haven't pursued it (1) I know it will mess up my security system because we called our security system.  ( 2) I don't want an internet phone I want a landline.  Otherwise why have a phone I have a cell phone.  I guess I'm going to switch to AT&T I don't need the hassle.  I just want a phone not all those add ons.  Guess if my internet is also not going to work I'll just keep Cox cable tv and find another provider.  :(