No refund for returned goods

My mother returned a blanket that was false advertised (advert stated that she will receive a second one free, which never happened). We then followed all their procedures and returned the blanket with proof of payment for the fees incurred from the couriers service as that is needed for them to process the refund. It has been close to a month and we're still haven't received the refund or at least received some sort of feedback. They promised that the refund should take about 7 days to be processed, I think they meant 70 days!!!