I personally prefer to walk away and leave it to the customer's conscience. I don't cope very well with stress, and it just does my head in to deal with people who have no intention of paying.
I have one ex-customer who owes me from months ago. She phoned me on Wednesday, pleading with me to clean her windows. I told her I would when the money she owes (I gave her the amount) is in my hand. She agreed to pay.
I arranged to go round the next morning at a specified time. When I arrived, the curtains were drawn and there was no answer. I left a note saying I had called, and drove away. Two minutes later she was on the phone apologizing for missing me, and could I come back. Dutifully, I did. When I arrived she offered me an amount which was less than the clean she was hoping I would do. I repeated what I had told her over the phone that I would clean when the total amount owed was in my hand. She then said she would go straight to the post office to get it. I said that's fine, I will come back later when you have it. She then got stroppy and questioned whether I trusted her. I replied that I have been waiting nearly a year already for payment for previous cleans. At this point she told me to leave. I smiled, said ok and did.
I felt so much better, knowing that she failed to get one over me this time, and look forward to ignoring her phone calls in a few months time, as I know she hasn't a chance of getting her windows cleaned by anyone else.
To the OP, though, I admire your tenacity and am very pleased that your perseverance paid off, leaving you with your money and the ex-customer with a CCJ. You both got what they deserved.
John