Left high but not dry

I recently purchased a megamaster fireplace and had it delivered (1km from store). It took three days but they did say that they were slow. I then had to purchase the chimney set online as there was only stock 30km away (Constantiaberg). I opted to pick up myself and invest in the trip as the cold front was approaching and my installation guys were ordered for the next day. When fetching the chimney I noticed that the box was open but assumed this to be part of their check. When I got home I noticed a part missing (ceiling plate), without which you cannot complete the installation. I managed to get hold of the sales floor guy (Shameeg) who sent me a picture of the missing part - which he noticed in the store. I then asked the guys to please please deliver the plate asap so that my installers could finish the job on Saturday. I was assured by Shameegs manager that it was in hand ONLY after trying to talk his way out of this responsibility, trying to blame the supplier, megamaster. After I told him about the photo that his sales guy sent of the plate, he finally agreed. Saturday came and went when I received a phonecall and WhatsApp message at 21:45, with the sales guy checking up, as he was off for the weekend. He then committed to following up on Monday. And again on Tue. Tomorrow will be Thu and still no word. In short - if you want to buy something of value and hope for an average level of customer service - don’t go to builders in Constantiaberg. They are leveraging a monopoly and will leave you hanging - ultimately costing you more money than you thought you would save.