I've got a customer who doesn't seem to want to pay me. She owes me for two £10 cleans and I've had no luck getting paid so far. She lives in a flat in a village a couple of miles from my other work. I only spend one morning every four weeks in the village. She first approached me as I was cleaning another flat in her block. We agreed a price and agreed on four weekly cleaning. I cleaned the windows there and then and she paid me straight away. Part of the problem is my fault, I didn't take down a name or contact number or ask her to pay online like the rest of my customers in the village do so I don't have to go out of my way to collect. She wasn't in for the second clean so I left a card and asked her to contact me to arrange payment. I didn't hear from her. I let it go and cleaned the flat again four weeks later. She wasn't in again and I left another card. I'm pretty sure she's just taking the piss now. She's got my contact details and hadn't bothered trying to contact me. Last week I hand delivered a polite letter asking for payment within seven days and I've still heard nothing. Part of me thinks I should let it go. It's only £20 and it only took ten minutes to earn. Another part of me wants to take it further. £20 is £20 and I did earn it. What would you do?