In contrast, despite the multiple frustrations of today, the thing that finally made me explode was that Mum kept jamming the phone down without saying "Good bye". She's not very accurate replacing the receiver, so I prefer some warning that the conversation is over before my ears are assaulted by the extremely loud clatter of Mum slamming the thing down in several attempts.
After the umpteenth time, I called her back and told her off about it. I feel pretty guilty about being angry with her. But she'll have forgotten any upset in the time it's taken me to type this, so I need to let it go.