Generator reimbursement

We built a house which was completed in September and got part of the build there was no electricity on site. We were told by the land agent that the developer would reimburse the cost of generator hire however we sent the invoice of in July and have had no response. I have called 6 times and the receptionist said she will chase up with accounts but still nothing. I have kept the email from the land agent that states the developer ' will reimburse the cost of generator hire'. Does anyone have any suggestions on how to get my money back?

Take it to A Current Affair