Thank you Trippy :

and thank you Nathanael - here goes:-
Specific and somewhat snooty but designed to unequivocally dump and make you feel superior.

Dear Mrs Custy,
Several times I have attempted to clean your windows over the last few months and have been met by various obstacles.
In October 2009 you turned me away because you had your "kitchen being fitted". This I accepted with good grace as you had until that point been a reliable customer although why having your kitchen fitted should impinge upon having your windows cleaned I fail to comprehend.
In January 2010 you informed me upon my arrival "that it was too cold" and due to the exceptional conditions - even though the vast majority of my other customers welcomed my arrival to clean their windows and some of whom even commended me upon my diligence - I once again accepted your cancellation with equanimity.
And finally upon my last visit in April you told me "not to bother" due to the "volcanic ash" making it not worthwhile.
I bit my tongue and walked away for fear of venting, like said volcano, my true feelings- but now feel compelled to inform you that I am removing you from my window cleaning lists as you no longer fit the profile of a reliable customer whom I wish to keep.
I hope you understand the reason for this and appreciate that I cannot set up my round for a day's work to be regularly given what are frankly excuses and non-reasons for my not continuing to clean.
I wish you all the best in finding a window cleaner that will suit your requirements.
Yours sincerely,
Bruce Willis
Or if it's because you want to dump several due to "can't be assed at such low prices it-is" try this.
Dear Mr Custy
I would like to thank you for being a customer of mine since ___________ (WW2; the last "Hung Parliament" etc ) but have to inform you that I have recently been awarded contracts to clean a large commercial premises in ___________ (name a place about 25 miles away).
This has sadly caused me to review my round and I feel compelled to no longer call on my customers in the _________ (name area) as my time is limited.
I highly recommend Squeaky & Tosh a.k.a. Raggit and Runn who will take on any old dross to supplement their dole money. They can be contacted on 07XXXX XXXXXX.Yours etc
Dave Willis
That last bit in red is of course optional!
