Re: BT let me down
"also informed me that there wasn't an engineer available for that slot. How is this even possible we had an appointment ready"
Usual answer is that they've "run out of resource" (also known as: run out of engineers).
Also, many utilities are moving over to workers "picking up" jobs from a despatch system. Your appointment would be put on that list to be picked up by an engineer, however if they're all busy then no-one turns up, and you don't get to know anything.