Mcdonalds delivery is the worst

I am truly disappointed with the service i had received from McDonald's Craighall, I ordered a meal at 16:30 on the 23/04/2018 and was told that my meal will be delivered to me at 17:20 I had to wait till for this meal until 19:00 truly disappointed, I feel like i wasnt given any regard as a customer, the whole point of the delivery time is that the meal gets delivered at that time. This is by far the worst service ever, for a big company as McDonald's they should have the delivery system in order by now.