Flat and sale agreement

While selling our flat we agreed on a buyer initially through a broker. The broker prepared a sale agreement on behalf of the customer. Her sale agreement looked everything favorable to the buyer. Then I was put on hold and said we were not selling the home at the moment because I felt the broker/customer was not genuine. At the same time, I got another potential second buyer. Also, he quoted a selling price a bit higher than the first buyer though was still selling it for a loss. we liked his (second buyer) sale agreement and we finalized it and sold it to him. Though I informed the broker that we were unable to sell the home at the moment and transferred back her token advance of Rs1000 before selling the flat, the broker kept on calling me (via different numbers) to sell the flat for her. If I am not selling a flat, she also asked me to pay a lawyer fee for the agreement she wrote. But I have not signed any agreement with her(broker) or her customer. Her customer called me and he said not aware of the cancellation of this deal. The broker and her husband keep on calling me on different numbers though I blocked her number. Kindly guide me on what should I do? Any valuable inputs are much appreciated. Thank you, Swarna