I used to find myself being rude to telemarketers and representatives for other businesses that I needed to call to fix a problem with billing of a product I use from them, for example “cable “. It occurred to me, “would I talk to them in such a way if they were standing in front of me?”. Of course I would not. I never did it again. That was about 10 years ago.
You obviously don’t have my cable company. It’s all I can do to not go in in person and cuss them out up one side and down the other. It’s out a dozen times a day 24/7 and due to their fuzzy math we’re being charged higher than advertized rates.