Staying Positive After Negative Customer Behaviour

Some customers really need to get a professional mindset when dealing with their suppliers. They need to realise that, just as they will react badly to poor or unprofessional service from a retailer, we will react badly to their behaviour.

In the past few days, I've had more than my usual share of negativity from customers. In no particular order, I've had to deal with:

1. Customers who, despite numerous visits, phonecalls or notes telling them when I'll visit, etc. never have the money to pay for the goods they've ordered, yet get upset when I ask if they still want them.
2. Customers who see it as a God-given right (judging by the reaction when I catch them at it) to short-change me.
3. Customers who try to pull a fast one regarding free replacements for items they've not bought from me.
4. Customers who demand refunds for items with no receipt to support their refund request.
5. Customers who, despite never being in when I call, and never taking the opportunity to call me back using the phone number on the numerous "sorry I missed you" slips, still harangue me when I finally get them to answer the door, before refusing to pay for goods they've ordered.

As always, I'm polite, assertive and calm in these situations, despite how I feel towards them.

In every single case, I've thought long and hard about whether I actually want the hassle of having these people as customers. Some will never get a catalogue from me again, some will get a second chance.

How do you deal with your negative customers?