I was on the recieving end of this kind of thing a couple of weeks ago as some of you may remember.
I think the main thing to rememer is we are all in business not charlty - but that doesnt mean we need to cut each others necks! there are literally millions if not billions of windows in the UK, there is no need to fight over them OR to cut hoses over them (although i would have loved to have seen Bumper do that).
My best advice is this, if a customer is not happy with their current cleaner then that cleaner has more than likely done something wrong and once that trust is gone its gone. However the customer could just be a t**t and get a w/c then bin them 2 cleans later in which case RO you will know about it soon enough.
I always practice in business how i think it should be done, by not under cutting others and by not actively stealing other w/c work! It has happened where ive quoted for work then the customer says your £2 cheaper than the normal cleaner ill bin him - in this position what can i say other than 'that wasnt my intention?'
However RO if you are intentionally going out to 'steal' other w/c work then my man in my opinion your a g*t and ill cut your hose myself! and i dont mean your WFP hose either!!!!!!
DC