Non working item sent back but no refund to date

I returned an item to TakeAlot on the 18th of December and have yet to be refunded. They have received the goods but nothing has happened to date. I have followed up and escalated this matter 4 times now and no results. This is terribly disappointing as I have only received good service from them in the past. The item costs R1499 which is a lot of money. Please can someone sort this out ASAP! The reference is RRN-c ********** for Aukey 30000 mah USB-C Powerbank with Quick charge 3.0 & PD 2.0. The item did not work which is the reason for return