You have done the right thing MalcG!
I dont believe in discounting business because a customer has decided to give someone else a chance of doing their business. If there is a problem of some description, if they are a genuine pain in the butt or chop and change on a whim - fine, but people have the right to source a supplier, try them out and make a decision. After all does anyone give all their business to one supplier, does everyone only use one place to buy their fuel? If so not many shop keepers would be in business if they kept turning customers away.
In saying that I also believe WCers should expect some degree of continuity and loyalty from the customer and if there is a problem be it price, service, quality etc the customer should have the decency to discuss it with you. I've lost a couple of customers because of numerous reasons and have heard they are now struggling to get a decent WCer but I am not going to them and they seem to embarrassed to approach me again. Its a funny world but if we keep a business heads on our shoulders we should do OK.
I think you had a pretty genuine grievance following the way you were treated and would expect an apology for that but I think you are doing the right thing for your business.
Its all money in the bank Malc