An agency relationship cannot be established without proof of an agency contract, either written or oral, whereby the principal authorizes the agent to act on its behalf to create legal relations with third parties. The burden of proving agency rests on the party asserting it. Mere assistance in collections does not create an agency relationship. Where parties have previously settled similar disputes without raising a particular defence, and the party cannot prove the factual basis for that defence, a court may infer the defence is raised to delay performance. In interpreting government directives for debt write-offs, courts will apply the plain meaning of the specified date - debts "as at 30 June 2013" include debts on that date, not only up to 29 June 2013. A bulk water customer of a local authority is liable to pay for water supplied as a debtor-creditor relationship, regardless of whether the customer has collected payment from its own end-users.