Refuse to refund me for over a month

Hi i have purchased a large amount of goods from Tile Africa over the last few months, and when building was completed i needed to return a few items leftover. The Greenstone branch mentioned i return the goods for a refund. I am waiting for over a month for this refund. They refuse to reverse the card or pay me cash. The only option is eft from head office. I provided the details which was rejected by head office. I then provided a proof of banking for the same details, which in turn was refused by head office. I was told i have to provide another bank account, which i fortunately have and provided. Thereafter head office committed to paying several times over the last few weeks but refuse to payout the reimbur*****t. The branch in Greenstone have no solutions and basically its now tough luck for me, we cant do anything, as head office cant and wont pay into either bank accounts provided. I have called about 17 times chasing after this refund, every time i get promised a call back which doesnt happen and am losing hope that such a big organisation is so unprofessional and dishonest. Very disappointing and frustrating after all the money i spent at Tile Africa.