False advertising

I bought paint for over 1k and there was promotion being run at Builders warehouse in Kempton that we will receive rewards of 9K guaranteed. I activated my receipt and all I was given was a R200 picknpay voucher which I still don't have over a month now. The adverti*****t clearly stated that it is a guaranteed reward of 9k not up to but the actual 9K. I tried following up with plascon but everytime I get through to the marketing department the phone just keeps ringing. This is false advertising and they don't follow up on their clients.....I am greatly disappointed as I wanted to buy Dulux but because of the false 9k guarantee rewards we bought Plascon. Advertising should be properly done especially with big companies such as Plascon