Item not refunded in nearly a month

We bought a 2000W 230Vac 1 Ph Mobile Ups Modified Sine Wave inverter with 2 12V 102AH Deep Cycle batteries(order no. D 3874) on 18 November 2022 from Step Building Supplies. The total amount was R14 734.06. We cancelled the order on 21 November 2022, before it was delivered and ask for a refund. They requested some documents from us, which we sent on 23 November 2022.

We phone them on Tuesday 6 December 2022 to find out why we didn't receive our refund, as they promise to refund customers with in seven working days. They told us that they only pay refunds on a Thursday. We then asked them if we can expect the refund payment on Thursday 8 December. They then told us that they will only be able to refund us on Thursday 15 December. They couldn't give us any reason for the delay.

On 15 December it will be nearly a month since we requested a refund. We are very unhappy with the above-mentioned situation.