Time was, that was a simple mechanical operation, to get your money back from a public phone if the call didn't go through. The world of modern kitchen appliances is rather more complicated.
If it was whizzy enough - by comparison with what I was brought up with - to have a couple of knobs to twiddle round a scale of printed options that told you what was on offer, now we have slimline, streamlined multi-functional indicators with discreet hieroglyphics (cheaper to print different manuals for different languages, which is no doubt why I've got an additional booklet of instructions for the oven in Czech and Slovak).
Take the dishwasher (not literally, of course). It has some sort of sensing arrangement to tell you when it needs more salt, which means telling it how hard the water is. There's a table offering four (count 'em) different ways of measuring hardness against the possible machine settings. Most Londoners would imagine we have really hard water, but of course it's passed through a lot of (ahem) human filters since leaving the chalk hills, and according to all four of the measures on Thames Water's website, it turns out to be barely half way up the available scale (one wonders where on earth is at the top).
But trying to get that recorded on the machine..... well. It turns out that the indicators for different sorts of wash also serve, in the right sort of combinations, to tell you how to set not only the hardness scale but also to choose whether it beeps to tell you it's finished (haven't yet found a way of getting it to put the washed dishes away). This involves pressing one button till one light's on, then it blinks, then the one next to it blinks and goes on, and yet another blinks and goes off. Or not. Why is that one over there blinking and this one not? How do I get the blinking thing to stop blinking well blinking so I can start again?
I think I got there in the end, but I might as well have been randomly pressing buttons on the Tardis ("I'm not very bright and I haven't got my glasses on"):