History repeating itself

So it's me upgrading again. Decided on a handset, they don't have it in store so they ordered it for me. Now here's the fun part. First it will be here the following Thursday, upon following up on it I'm told it's not there, will most likely be here the next Wednesday. Followed up again and then it was maybe Friday because the truck came in on that day but alas, no phone yet. So there's this pattern forming. Promise after promise after promise. Been a customer for years now, having 4 contracts with MTN. Working between 2 stores in Middelburg and it's always the same thing. This is not really the shop's fault (even though there's zombie-like service with a general I-don't-really-give-a-**** attitude to customers). There was this one time I was waiting for over 2 months for a router and then receiving the wrong one at the end. So here's my question. Why does it take so damn long for you guys to do a delivery? And is there maybe contact details we can contact those responsible for deliveries so that I can make some fire under their arsses seeing that the staff at the stores don't really care?