The store initiated a marketing promotion which sells all sandwich packs for only $5 (normal price: $8~$10) between 12 pm to 2 pm However, the customers cannot get this promotion if they spend too much time in a queue and the time passes 2 pm in the POS system

For example, even though a customer picks up the sandwich before 2 pm and waits in the queue for checkout, if the queue is too long and the checkout is done after 2 pm, then the customer is not able to get the discount

As a result, a few customers were not very satisfied as they were not able to get the discounts and lodged a complaint to Fair Trading NSW

Recommend to the operating manager how to handle this issue?