Thanks for your enquiry.
I'm afraid to say that nearly all Estate Agents agreements state that if any Buyer is found, during the term of their agreement that they are entitled to their commission if the Buyer proceeds and completes. ie even if the customer does the hard work and finds a Buyer, then the Agent still gets paid!
This is slightly ridiculous but that's the way they operate.
I am sorry this isn't the answer you were looking for, but if I have assisted, I would be grateful if you could leave positive feedback.