Hello I am a solicitor with over 15 years experience. I will try to help you with this.
Can you just tell me what sort of work was this? How much was the contract price. How much was the deposit?
the work was to canvas window cleaning customers.i paidv £100 and the contract price was £1000
In the absence of a clause about late cancellation you have done nothing wrong. What was the purpose of the deposit if not to protect them from this sort of thing. Late cancellation is routine in business and unless there is some deception or false representation on your part then they have no legal basis to sue you. They should ask for a larger deposit!