All orders shall be placed by heads of departments or Town Clerk-Treasurer. In all cases, bills against the Town shall be refused payment unless accompanied by written purchase order approved by the Mayor and by sale or delivery slips showing receipt of each item embodied therein. It is hereby made the duty of the Town Clerk to return all such bills against the Town not accompanied by such purchase orders and slips. (Ord. 173, 3-15-2011)