Collecting from deadbeat customers

Hire a hooker (male, female or transvestite is an option) and tell them to go visit his wife. Send his wife flowers that say some other girls name on them. Buy him a subscription for a gay mag and request they be sent unwrapped to his home.
No warnings or threats just do it.
At that level, "business" and "nice", do not belong in the same sentence.
Daryl