Refunds on products purchased

I bought a TP-link system from Incredible Connection on Saturday after explaining to the sales consultant the challenges I have at home and they said that this unit would work for what I needed (long story short, it didn't work). On Monday I went back to return the unit and asked for a refund and was told that the refund would take 24-48 hours to reflect (this is also after they deduct a 15% handling fee).

48 hours later, there was still no refund. I phone the store again and was told by a different consultant that it takes 3-5 days and which point I said it is unacceptable and I would like to speak to a manager. When the manager got onto the phone and apologised about the confusion and that the refund time is actually 7-10 working days. Why does the "goal post" keep getting shifted on the days to refund?

This is a very simple release of funds that needs to happen and there is no reason why it should take longer than 48 hours (let alone 7-10 working days).

I was told to phone head office if I want to escalate further. Absolutely pathetic customer service.