Sometimes there's just that one customer. The "Problem Child" customer that you don't like having to deal with. The one who totally know is definitely (probably) making things up to try and get a free float. And they're such a nuisance! What can you do about that? Obviously you don't want them getting vengeful if you tell them to kick rocks and spread lies about you.

How do you handle that situation? Well, Graham and Ashkahn lay out some nice ground rules for how they handle people and it comes down to setting clear boundaries that at least appear rigid on the outset. Then, if those boundaries are crossed, the reactions you have are totally expected.