Treating people with respect and dignity seems to be a hard concept for some people to grasp.  Even if the old saying "the customer is always right" is true, that doesn't give anyone free rein to be nasty, degrading, or hateful to people in the customer service industry, or any industry for that matter.

This customer found out the hard way that you catch more flies with honey than you do vinegar after he was belligerent and vulgar to a credit union employee over things that were his own fault, to begin with.  In a temper tantrum, he demanded she close his account and that is exactly what she did in a dual serving of malicious compliance and instant karma.