I decline to be polite in these situations and usually resort to threatening to insert the item into the least comfortable orifice of the perpetrator of the annoyance and storm off to shitpost on a suitably sized forum to try and ruin them.
No excuse for that sort of rubbish. It’s more the person doesn’t want to help you.
As someone who has both used my method repeatedly to great success, as well as having worked in customer service, I assure you that rudeness only works to reduce your chances of success. Whether they
can’t or
won’t help, if you thank them and ask to escalate, you might get somewhere. If you yell and insult, and then ask to escalate, you’ll either end up with the manager known to be a hardass, if not with a colleague pretending to be a supervisor, who will also block you.
(When I worked in retail, I had one manager who was a total bitch, and several guy managers who were reasonable and nice. If a customer wanted something outside of normal policy and was nice about it, and I thought they should get it, I’d ask one of the guy managers to do it. And if the customer was being rude, I’d stick to the letter of the rules, and if they insisted on a manager, I’d get the bitch instead.)
So while it can be cathartic to let it out on the person on the phone, 90% of the time they aren’t to blame, and when they are, you aren’t gonna get what you want by yelling, instead stroke their ego and suddenly things become possible.