incrediBILL - 7:12 pm on Apr 27, 2013 (gmt 0) [edited by: incrediBILL at 12:53 am (utc) on Apr 29, 2013]
Send them a bill for thirty minutes consultation time.
One way to stop disruptive time suck phone calls is to keep a five minute timer on your desktop, phone or tablet and click it the minute the call starts and you have an alarm which could be a ringing phone sound, and an easy escape.
Tricks of the trade ;)
In all seriousness, time management makes or breaks consultants so customers on the phone are the death of productivity. I used to have a client that liked to stay on the phone when his website had a problem until it was resolved which is very distracting and takes a lot of time when someone that doesn't know squat about it is sitting there offering unhelpful suggestions nonstop. after doing this a time or two I finally put my foot down and told him I can't focus on the phone and he was possibly losing more sales the longer it took me to resolve this which got him off the phone.
[edited by: incrediBILL at 12:53 am (utc) on Apr 29, 2013]