If you react angrily, you might escalate the situation and both you and the customer could end up even more aggravated than you already are. [substeps] Pay attention to your volume and tone of voice.
[header] How to deal with a cursing person [title] Stay calm. [step] Do not reply with anger just because the customer is being immature and working through their anger in an unhealthy way. For instance, if you're on the phone with a customer, do not hang up on them as soon as they start cursing.