Not refunding double payments

On the 27th of December me and my husband went to buy a few things at Mr Price sport in Phalaborwa mall. When making payment we tapped the card machine with the phone it clearly showed on the phone with tick to indicate approved however the teller assistant said the payment did not go through and quickly put the slip printed and card machine under the counter and pulled out another card machine.

And it was made out that the card machine has bad linkage hence it didn't go through.

So my husband payed again but before leaving the store decided to check the bank on his cellphone banking and it showed both transactions went off.

We immediately notified the staff of the issue they gave us a for to fill in and said it will be refunded by Monday /Tuesday 29/30th of December.

We received no further communication and when phoning them today they at first pretended not to know about it and then eventually said yes they remember and the person who handles the refund is still not back.

They said they would phone back by end of business and still have not phoned as yet. Still waiting on a call with no to little feedback