[Paul Coleman]

I know this sounds radical but why not tell the truth that some other window cleaners were being intimidating and you just want a quiet life 

[Jack Wallace]

A friend of mine got on the wrong side of the pikey's. they laid a drive for him, (dont ask, I was amazed he let them as well) after the job was done (very very badly) they doubled the price and intimidated him till he paid up.

I would NEVER work for these people. they are crooks.

So in answer to your question. Dont bother being "nice" just drop them