Wrong Charges TWICE in FIVE Days

I have changed my Healthy Food back to Pick n Pay and have now come to regret this. I have shopped at Pick n Pay twice in the last 5 days and both times I was charged incorrectly. Lynnwood Ridge mall made mistakes with promotions and scanning of products. Then when I got a refund from them after the managers on duty were border-line rude, I went to Hazeldean Pick n Pay to draw cash and saw Joghurts on sale. When I checked my slip the following day, I saw that I was charged incorrectly. After altering your Facebook team I get told that the promotion ended on Sunday - HOWEVER the special price was still marked in-store. As far as I am aware from my marketing expertise, if a price is marked in-store at a lower rate than on the system, the lower price will still be used. So please explain this to your store and social media staff! I also find it such a waste of time that I have to drive in to the store to get a refund. Please process the refund on the joghurts and ensure your systems are uploaded properly. The service I have received from you in the past week is atrocious.