Phone posture is another basic skill that needs to be mastered.  Yes, you will come across angry or rude people and it is human nature to feel upset or want to retaliate – neither response is advisable, you will immediately lose their respect.

You need to realise that your call is an interruption to their day and a rude response can be a reaction to some news they are dealing with, let it roll off you like ‘water off a ducks back’.