Diabolical service from Pick n Pay online shopping

I have dealt with many customer service centres in the UK, USA, Australia and of course South Africa. Today I experienced the worst customer service of my life with Pick n Pay online shopping. To day that the lady talking to me should be fired is putting it mildly. I started putting my online order through mid month when I was able to book my delivery date. I added or took off items and always received an email saying my order had been updated. The last update occurred on 1/11/2020 at approximately 2.00am. and confirmation was received. I get my invoice today 1/11/2020 and 7 essential items from my last update have been left off and items I had cancelled were on. 3 other items had been substituted which I accept. I phone customer service and this lady to enquire and this lady asks me for my order number which I gave her. I told her the cheese on the invoice had been cancelled so why was it on my invoice. She asked me when did I cancel it and I told her a week ago. She says the invoice is dated 1/11/2020 which is today so how could I have cancelled it 2 weeks ago. I said I add and subtract from the time I order and she shouted me down and said the invoice is dated 1/11/2020 and I've already paid for it so I'm talking *******. I could not make her understand the basics if the system as she kept on shouting me down. I then asked to speak to someone who knew what they were doing and she said "hang on".I waited 22 minutes but to no avail. When I phoned back I spoke to s very nice gentleman named Bongo who tried to rectify the situation but it was all too late for him to do anything. Been doing on line shopping since beginning of lock down. The first month was a shambles but everything has been first class since then. But today was a very different story. Pick n Pay will probably come out with their sorry for your experience but that does not begin to solve the problem. I am 70 and have a 98 year old mother who I look after and cannot leave alone. We also cannot venture out in these times of covid. This was why we did online shopping. With have to try and make other arrangements from now on. Sorry for the long review.