If I had a customer that would want to cancel on the doorstep the answer is" no " as I have arrived which has a cost, so I do not accept this and state this in my term of business.If they phoned a day before yes. Do that too often and drop very quick. Some folk are just trying to push and see what they can get away with. From experience I dont allow then to much rope.I don`t argue just state how I run my business. If you run a business they will treat you that way, run it to sloppily they treat you that disregard.If I am going to dump I will tell them what I am going to do. Firstly it build character and strength to handle my business, and it shows them my mettle. More times they apologize and I them keep then on.They are quite I find they are flabbergasted and back down quick.