Last month, window cleaning sales rep knocked on our door. Initially we said yes to a window clean, but then after googling the company, changed our minds, found the sales rep and cancelled. Shortly after we had a text message with an appointment confirmed. We emailed and texted to cancel the appointment, and also asked for our details to be removed from their system. A few weeks later we had a message saying the window cleaners were coming the next day. We emailed, texted, and phoned to cancel, and also asked again for our details to be deleted. When we got home that same day, the window cleaners were spraying water on two of our windows. When they saw us they stopped and quickly packed up. I told them they should not be there, they said there would be no charge. A couple of hours later an invoice arrived. We will not pay a penny. Seems to me that they are breaking the law and we should report them. Am I being unreasonable?