Disruption is a time-tested method of resolving conflicts. It works like this:
Step 1: Accuse the customer of being wrong. This is the most important step. It sets the tone for the rest of the conversation.
Step 2: Deny any wrongdoing. This is where you assert your innocence and deflect blame.
Step 3: Attack the customer's character. This is where things can get interesting.
Step 4: Offer a half-hearted apology. This is to make it seem like you're actually sorry, but not really.
Example: You: "You're being unreasonable." Customer: "No, I'm being reasonable." You: "Fine, be that way." Customer: "Whatever."