Thank you everybody.
I will write a letter to my customer and i will apply your suggestions. It is a pleasure indeed to be in here like-minded people.
Again, thank you for all your advice. 
You have taken all these responses in good heart. Fair play to you.
However this works out with the customer, you should learn from this how to cover yourself in the future.
Maybe checking the job beforehand and making note of any possible damage that the customer can try to blame on you afterwards.
Whatever happens you need to look and act as professional as you can or you can end up coming across many customers like this one.
Unfortunately if you give some people an inch they will try to take a mile.
Maybe you should start a new thread detailing your cleaning experience and background and ask how you can improve your service and gain more work.
Good luck to you.
mark
ps apologies for my earlier remark. It seemed funny at the time.