Supplier unable to retrierve my returned item

I was experiencing some issues with a headset I bought with Takealot. I logged a return and opted not to credited but rather for replacement. The return was logged on the 6th December. The item was received at the supplier's evaluation centre on the 11th Dec. The supplier closed the 15th for holidays and reopened the 2nd Jan. On the 3rd of Jan'24 I asked the agent(Bianca C) how much longer before I can get feedback. Almost that same day I got a response that my takealot account has been credited. The supplier cant replace my unit as they are out of stock. And they cant fix my headset. I told the agent that I dont want the credit. I would like my old item back. To which she responded and said the supplier had sent it away and are no unable to retrieve my item. I then told her the supplier will have to replace the item. I can see from Takealot's website that the same headset is available and in stock. Surely they would then be able to replace. Bianca responded that different supplier's are being used. I feel Takealot and the supplier is now running away from their warranty obligations. I want my item replaced and they must give me back my old item.