The courier guy is the worst courier service in South Africa

I have a business and utilise the courier guy almost daily. From two locations. One location...the driver is spot on. No problem. The other location is a headache or rather a migraine. After complaining...it never got better. They offer a booking slot on the portal for time. The driver is either too early or absolutely late and even speaking to the driver never helps. It gets worse and worse by the day and the useless area manager doesn't do much about it. Is this fair? They offer a time slot that is never adhered to. Why?