A company is doing work out the back of my house in a developing area. The dust levels are horrendous, and I've made many complaints to the council. The company offers to clean the outside of our house or give us $500 ( compensation). A representative from developer comes around to my house at my request. I made a counter-offer with give me $1000 and clean the outside of my house. The representative says he will have to talk to managing director who returns home on the 25th of June. On 14th of June, a man comes to my door and gives me envelope with $500 dollars in it. I email Representative and ask him why this has happened. He claims it is a mistake and that no decision would be made on my offer until managing director returns home on 25th of June. On 25th of June, today, I received an email saying managing director said I accepted the $500 from their original offer and therefore matter is over and done with. Advice please under contract law, thank you.