We have been back and forth with a customer since early May. He chopped and changed his mind several times over the course of the quoting period. During this time, we've made a massive error in costings. We didn't add the additional equipment/materials needed and are now going to lose approx. $10,000.00 if we complete the job. We have not received a signed copy of our contract back as requested. The customer has paid a deposit, we want to refund his deposit and walk away, no hard feelings. Where do we stand under Australian Consumer Law?