Poor online shopping process

Pick n Pay's online shopping experience is quite poor. A third of the products I ordered weren't delivered. One of the products was swopped out with an unsuitable substitute. I was however able to return it right away with the delivery guy. Having selected a particular delivery time, they phoned me to try and change the times. They ended up confirming my original delivery time, and then the delivery guy showed up 2-3 hours early anyway. It was lucky that I was at home to receive the delivery. If you're not going to fulfill the entire order, then you have to first contact me to find out if I still want the remaining items. It might not be worthwhile to pay the delivery fee if the order is now substantially smaller. I planned on getting the whole order, and I then had to go out anyway to get some items. What should've been a convenience turned out to be anything but. They have not provided a final invoice for the items after the undelivered and returned ones, but have debited my bank account.