Staying calm on a difficult call
An upset customer is almost always frustrated at a situation, not at you personally - even when it doesn't feel that way in the moment. Holding onto that distinction is the single biggest factor in staying calm.
A useful structure: acknowledge what happened in plain language before you try to fix anything ('I can see why that's frustrating'), ask one clarifying question to understand exactly what they need, then explain what you're going to do next in concrete terms. Skipping the acknowledgment and jumping straight to a solution is one of the most common reasons a call escalates further.
If a call genuinely crosses into abuse, know your escalation path before you need it - most support teams have a clear process for when and how to hand a call to a supervisor, and knowing it in advance keeps you from freezing in the moment.