Istore menlyn poor service

On the 18th of August 2023 I trade in my Iphone 12 pro max for a cash back, they first informed us that it will take 72 hours until 14 days, they never communicate with us. When we follow up they informed us that it is 14 working days, after the 14 workings days they requested proof of banking details. It is now 21 days and we are still waiting for the cash back