Andy has a contract of sale drawn up which Sarah signs.Unfortunately for Sarah she discovers that the yacht is closer to 15 years old than the 5 that Andy claimed.Sarah approaches Andy with this information and demands her money back.Andy has a copy of the contract and explains to Sarah that none of the terms of the contract mention the age of the yacht.Andy explains to Sarah that they are only bound by the terms of the written contract.

Since the collateral promise is not consistent with the terms of the main contract.

which section in Australian Consumer section corresponds to this case?