Laduma does not want to refund me

I called the store and requested a quotation, which was then forwarded to me. I made payment immediately as I needed the building materials urgently. I was then told the money needed to be cleared at thier Head office which took 3 days. I ended up buying the Timber elsewhere as they needed to use it urgently and requested them to refund me the difference of R2400 as I ended up only taking goods that amounted to R10200. Today is the 8th day and I am still being told my refund is being processed and I should get the money before the end of the day. And that has never happened. I have called the store almost everyday, it's inconvenienced me alot as I need the money for my project,as I had a budget in place for all the items to be procured.