Discount not deducted with no response!

I have purchased an item online and the website noted that there is a R1200 off plus an extra R580 off for rewards customers - acount customers are automatically members.<br> The R580 was not deducted from my purchase amount. I have sent 5 emails with no response. I have also phoned the call centre twice and spoke to a Mark. He promised to get back to me. Its now almost two weeks with no resonse! A message was also sent on the website to contact me in this regard with no response!!<br> If this is how they treat their account holders...