Ever have a customer who has provided more headaches and hardships than they paid for? Sometimes there's those clients who think that just because they're the ones paying for the service that they're in total control and can manipulate their way into receiving the best possible "deal".
I can appreciate somebody who shops around... I implore people to. What I can't appreciate is a customer who takes the deliberate stance of being difficult and hard to please - I truly do whatever I can to make a customer happy so I know that if a customer is unhappy with price and payment policy (one bill a year - harsh, I know) than I've got a customer who would be better off somewhere else.

I've got plenty of good deals - and when a client tries to squeeze every penny out of an already squeezed package, well...
is it really worth the aggrevation?

When a client doesn't pay on time, am I being too generous to let them off the hook time and time again by giving them extensions and not terminating their account? Am I being too naive to think that because I may know this client socially that they may indeed be a loyal and appreciative customer?

What about when a client realizes you're not going to dance for them and they entertain ideas of moving to another provider - a provider of far less quality? Is it worth fretting about or is it better to just cut your losses and move on?

If the customer is willing to abuse the service provided to them, than they should no longer be welcome as a customer.
Nobody likes losing a customer, but sometimes it's the only way -
I hate to see them go but love to watch them leave.