Foshcini Mall of Africa are ****mers!

I paid for a transaction on the 21st of December. The cashier assisting me made a mistake and I was meant to pay twice and they performed a refund. They said that money would reflect in my account the next day. I went there yesterday, and found a different manager who requested i even send my bank statements to check however did not give me anything for me to see how far of my pending query or any details of when I will receive my money. It is now the 28 of December. I have not received any call or anything update after they made me leave my details about my pending refund. Why was I made to pay twice if their systems fail. Why is this now made my problem and why am I the one made to drive to foschini mall of africa to check on the query?!