My nomination is Vodafone. By miles.
I rang them earlier, got the "we're all busy, do you want to book a call back?" option. So I booked it. They have now called back and I have now been waiting 35 minutes listening to their music interspersed by "sorry for the delay, your call is top priority and will be answered next" every 60 seconds.
In the time I've been holding I've been for a wee, husband has cooked the pasta to go with the bolognese, served it all up, mine's going cold while I wait for Vodafone to give me a few moments of customer service.
How crappy can a telecoms company actually be in 2022? I can only assume there is one person taking calls for Vodafone tonight.