Dis-chem's poor handling of on-line orders

I've ordered on-line from Dis-chem twice during lockdown. Both times there were important products that they didn't deliver. First time 3 out of 8 products were NOT delivered (38%) Second time 7 out of 17 (41%)! I didn't receive a message to let me know that the complete order could not be fulfilled. I would have cancelled the order, had I known. And they don't do back orders. Not only that, with the second order the wrong invoice was in the box! Also, I was not given a refund of the amount that was not delivered with the second order. If you can't do something properly, don't do it at all, or at least give me options. I know Dis-chem will use the "unusual circumstances" and "high demand for orders" as an excuse. They shouldn't. If you have competent systems and employees, it should not be a problem. Just on the side - their on-line site is extremely slow, it's like pulling teeth to order. I will have to try Clicks next time or take a risk and go to the store.