Withholding my funds for a product they didn't supply

I had great initial dealings with Zane the owner who is friendly and professional in-store and he knows his game. I got my mattress delivered after a bit of a long wait but that was ok. I'd paid for the mattress and a R750 mattress protector. The protector didn't come with the mattress as i was told it was "out of stock." After 2 months of forgetting about it and also hearing nothing about it, I whatsapped to ask for my funds to please be returned.

I was told the accounts department lady is on leave/pregnant ...then Zane offered me pillows or a "spare" protector and I said I didn't need them, I just wanted my funds back. It eventually got annoying that they seemed to not want to refund me.

Another few weeks went by after saying I will get my money but nothing - I find it really strange why a large company can't refund a small amount when it's not theirs to keep? What was initially a very pleasant sales encounter has now soured for me due to their refusal to give me my money back; it can't be a cash flow issue as it's not thousands of rands it is a mere R750 - please REFUND ME Mattress King, as it's ********* to keep funds for a product you didn't supply now and that I now no longer need.

I gave them 3 WEEKS warning that I would go on Hello Peter and still nothing - very disappointed in their refusal to rectify this situation and I want my R750 returned ASAP or next I will go on Facebook just on principle.