Calling a pizza delivery service to order 400 large pizzas, each with extra anchovies.
Start the call by asking for the order number, then proceed to ask for increasingly ridiculous modifications to the order, such as:
When the pizza delivery person starts to get suspicious, ask them to speak to the "Manager" and have them repeat the order back to them.
Continue to Prank Call Script 3-2: The Rebuttal Or, for a more advanced approach, go to Prank Call Script 3-3: The Prank Call Prankster's Revenge