Struggling for refund

I have been trying to get a refund for a watch that is a mere R900 and was bought on the 24th of February at your Central City branch, Mabopane but I keep being told they don’t have money for the refund, I then went to the Wondepark branch and I was told the same thing. I have been going back and forth trying to get a refund and it’s always the same thing, what can be the resolution to this because this has been an exhausting task.