How do you handle ppl who call the office and start yelling about a bill?

We never refuse to explain a bill, but a few patients have called and screamed bloody murder about some amount not paid by the insurance company and marked on the insurance statement (EOB-explanation of benefits) "Patient Responsibility" or "Insurance deductible." The amount owed could be as little as $20 and over $100 (depends on the ins. co). This office is a dental office and I mean ppl shouting and not letting staff get one word in.
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If people start shouting at you, simply say that if they continue to shout, you will end the call. If they continue, state that this call is over, and hang up.
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