Buffer Amount: Terrible service by Pick n Pay

Not Pick n Pay overcharging me for na offer. My total order amounted to R360.96 with free delivery and I get charge for a buffer amount which is R158.94 and that should be refunded once my order is delivered. 4 days later there is no refund on the order, in Total they deducted R529 on my bank card. On top of that they overcharge the liquid soap selected as substitute and yet that was on special. Linda M has provided any feedback or tried being helpful on the customer support.