So I was waiting for an order to be delivered and ...

So I was waiting for an order to be delivered and I was buzzed on my number, didn't know it was from Nandos.. I called a lil bit later and the guy said it's Nandos delivery... Imagine what if I didn't call back?.. the driver even told me that they are told to even send a please call to the customers so they call them back,if not,they should return the food back to the store so that the customer will have to collect it at the store.. so I have to use my airtime to get my order?.. it doesn't make sense..