Pick n Pay online shopping *******!!!

On just before black Friday 2018. I placed an online order with pick and pay. This was my very first time buying from their site online. I selected all my items and proceeded to pay. I added my card details and processed payment. I was asked to schedule a pick up from hyper by the sea in durban north, which I did for the 4th December 2018 between 12 and 1pm. DONE! Or so I thought. I arrived to pick up my order as indicated only to be told that my order was cancelled!!! Bear in mind I live all the way in Ballito, a 80km return trip. I was asked to call the call centre which by the way doesn't have a decision maker present. After 45mins on the phone a team leader Desiree tells me there is nothing more she can do as they emailed me the day before to say they were having a problem with payment, an email by the way I never received. I proceeded to ask her if that was the case why not call or a sms which is a more certain and definite way to ensure that the client is notified of a problem. To this she had no anwser. She told me that there is no one else above her she is in charge and that her final answer is she can not do anything tp help me a paying and valued at least I thought that, customer. The lady at pick and pay hyper than took the phone from me and also tried to get Desiree to assist more to which she said she will email someone else and get back to us. To this very date I have had no further communications from pick and pay. And now all the items I purchased for my Christmas holidays are at extra ordinary prices and I am left unable to purchase it. This ia unfair, why does pick and pay have such a flawed online ordering system and how is it possible that a simple team leader is the final say so? I want answers.