“and on and on. They don’t know what to do in response.”
I keep a phonetic outline of Hindi insults I got off of Google translate in just such cases.
You have to be subtle. If you have time, waste THEIR time! Drag them through all the bullshit questions you want to ask and then wait for them to transfer you to the supervisor and then hit him with the killer (I use a Mac).
Wasting their time means some old crotchety effer don’t lose a bundle on their crap. Take the time. Waste theirs.