I speak a language with a formal you and am constantly trying to use it to tell people to back off, but it doesn’t really work like that. That’s absolutely what I do in English with ma’am/sir though.
I used to work in a call center for an insurance company, so people would get upset and shitty with us. My default to “reset” politeness was to allow a couple beats of silence, then say “well sir/ma’am, xyz is what I can do to help you. Would you like my help?” It worked about 90% of the time, but drawing the silence out longer and adding more audibly sarcastic sugar on the sir/ma’am would generally work at either getting them in line or provoking them enough to cross the line so we could hang up on them.