Bad service and misleading pricing

Omthe 15th I placed an order for 6 x 24 cooldrinks which were on special on the website. Today the 19th December I went to pick n pay Newmarket to collect my order. When I got there I inform the 2 ladies who were sitting at the order desk that I'm there to collect, they just said I hope its not the cooldrinks I said actually it is. They just left me there and few minutes later they appeared with the manager "Rock" who then said to me they cannot give me my order because they are waiting for head office to confirm the price and that they will contact me to give me feedback. He said they have received orders for the same products however their system is not showing the price that was on the website hence they need head office to approve. He said they will call me. I left the store and 15 minutes later I received a email saying my order was cancelled. I drove all the way to Alberton to collect. I think pick n pay is just taking its customers for granted. Other people received their orders and suddenly I cant get my order yet I paid for what was advertised, drove all the way to collect only to be misguided. Why was my order suddenly cancelled after I spoke to Rock? Why was I not contacted prior coming to tgr to avoid wasting my petrol? What happened to the phone call I was promised? This is just nonsense shem. You are misleading people. I'm not happy with your service whatsoever. 4 days is a very long time to have rectified whatever issues instead of waiting for the customer to come to the store and not get what they paid for. If you could cancel my order few minutes after I visited the store, why didn't you cancel it prior to the collection date, now I wasted my time and petrol for nothing nxa.