Thanks for the link, Boggo.
An update on my earlier post re the statutory warranty.
The day after that episode, the convection/microwave in the same brand took on a life of its own, just turning itself on without anything in it, running for a minute in every ten.
Nine months old. Took it back, expecting another battle.
Not at all. I'd have been happy with part refund given I'd had 9 months of use, but was simply asked if I wanted refund or replacement, opted for refund, and full amount was paid over with a smile. So maybe management had done a bit of a rethink about their statutory warranty obligations.
I've learned a good lesson, though, i.e. not to ever buy cheap stuff.