No refund for defective product

In August 2014, we removed the fibreglass casing from our pool to find a perfect shell. We did research for painting our swimming pool. This company assured us that it was impossible for their paint to come off, as long as we treated the pool properly beforehand. Besides our own research, we contact them at least half a dozen times to get advice, before we eventually bought the paint and followed their instructions EXACTLY. The pool was left empty to dry for 2 weeks, we washed it several times, dried, vacuumed and painted it in October 2014. Six months later the paint was coming off in several places. We calledthem, left messages, but they did not return our calls. They send someone out eventually, who subsequently went on leave and never got back to us either. We persisted and eventually three months later they told us that they tested the batch of paint sold to us and according to the lab it wasfine and there was nothing else they wereprepared to do. Although the paint cost me over R5k, my total loss is R12k as it cost R6k in labour in order to treat the shell properly and exactly how they suggested. In addition it cost nearly, R1k for water to refil.