We have recently had $32k worth of renovations done to our home. Part of the original quote included $3k worth of scaffolding which was a separate line item on the quote. We also had another line item for guttering / downpipe replacement as well as a separate line item for the painting of our 2 storey home. We have paid in full for the job with the exception of the scaffolding as we have disputed the fact that the builder actually hired the scaffolding. Both the painters and roof contractors provided their own scaffolding, and neither provided per perimeter scaffolding as per the original quote, they both provided mobile scaffolding. The contractor is now claiming (3 months after the painting work was done), that the scaffold hire is now part of the painters quote, even though this was not listed as part of the painting work in the original quote. The invoice for the scaffold hire is now 7 days overdue and the builders are threatening to send this to a collection agency for follow through. Where do we stand legally under contract law given that he hasn't actually provided the service, yet insists on charging me for it? Does the fact that he hasn't provided me with an approved contract as per the Queensland Domestic Building Contracts Act matter in this case and is that an avenue I can pursue in response to his threat of the debt collection agency? Any advice would be greatly appreciated.