Judy,
IMHO you were not wrong in what you did.
I maintain and always have that when you the seller has received payment for the mdse. you are selling, the obligation of the buyer has been completed. Your feedback should be based on that person paying within a timely manner.
I don't agree in any shape size or form with those that hold feedback as hostage just to see what you write first.
As a matter of fact I no longer bother to post feedack for those people at all.

What is being suggested here by others is that if payment is made in a timely manner and the customer for whatever reason leaves you negative feedback, you, rather than trying to resolve the dispute should become vindictive?

Just to go off on a bit of a tangent and another pet peeve of mine, ever wonder why someone with 700 plus feedback comments and a perfect feedback score should be obligated to pay a vendor with a questionable feedback record first?
If someone was to get screwed in a deal such as I suggest, who do you think it would be?