I hate it when a customer cancels or tries to rearange after I have sent a "windows due for cleaning " text, it smacks of all being "one way", if they knew it was inconvienant on that day why would they wait untill they got the "calling tommorrow", message, surely its not beyond them to send you a message saying, we're away/having work done/scafolding up,etc.so could you leave this time.this would be a fair way, allowing you the opportunity to resheduale other work for that day,
One way customers are best given fewer chances. Strike two and this ones history!!!