I used to run an escalation support team - i.e. the guys customers got to talk to when L1 couldn’t solve their issues in a contractually-timely fashion.

If a customer was angry and abusive, and demanded to “talk to the boss”, they were escalated alright - but not to my team: the L1 guys would put their ticket back in the queue and their problem was solved mere minutes before the 6-hour deadline, even if the problem was trivial.