Customer service- Follow up

Need to rant.....Yesterday i placed an order via whatsapp to pick n pay acropolis. Everything was in order and i was informed my order was being processed. Then later in the afternoon one of the staff members (Rinesh) contacted me to inform that they did not have Super M milkshake banana flavor, if they could change it to strawberry and i said change it to 2x choc and 1x strawberry. I was then informed my order would be delivered the next day around 10-11am becaise of the high volume of orders they had received. So today i waited and when it was 12:45 i queried what time the order would be delivered only to be informed its only leaving at 1pm and all of a sudden my total that i had calculated was less than the original total. It took me 3 phone calls to get through to someone. To be told they are out of stock on certain items and i was informed. I must wait for rinesh to come to work tomorrow for them to query. Which i was not happy with so i told them a better solution would be to phone rinesh n find out wjat happened. When they called back they said there is nothing they can do and now i informed rinesh i wanted 2xstrawberry and 1x choc. There was another employee in the background who was informing jadene( the girl i was speaking with now) that she must just ask what i want now. Instead of admitting that they had commited a mistake. They refused to take any blame and just said there is nothing they can do because my question to them was "how can they decide to just change certain parts of my order without informing me?". To which the reply was " it wasnt me (jadene) that spoke to u". Absolutely disappointed with the customer service