Unprofessional service costing me money

I have always placed orders with ZANDO and never experienced any kind of problems but unfortunately that has obviously changed. I placed an order on Black Friday, I bought a pair of sneakers for R999 after a few hours I realized that there was identical adidas sneakers for R799 so I called your call center to ask for advice, I was told to place an order for R799 sneakers and send email of new sneakers (R799) old order and proof of payment for old order. I was told that my R999 order will be canceled and convert the money to R799 order and be given a refund of R200. I sent the requested email but nothing was done instead I’m getting email to pay the R799 and that R999 order will be delivered. I have been wasting my airtime to call and call but I’m not getting any help, I was promised that the Manager will call me but no call. Please resolve this. I used ZANDO because I know it’s very fast, safe and effective but you are starting to show me that I was wrong about you. The idea was for me to save R200 but instead I have used more than that in calling your call centers and I’m continuing to use my expensive data and you not even bothered to respond.