False Promotion Advertising

I bought a suitcase that says on Promotion for R899 a deduction of R400 from the original price of R1299. I ask the attendants and they confirm it, get to the till; nope, nothing like that; you pay the full price. I asked about the promotion and was told they don't know who is responsible, either I buy at the full price or leave it. To top it all, they deducted R100, and I paid R1199 as if I was being done a favor when the item was clearly labeled as R899. It feels like a serious ****!!!