Sharp practice and dishonest advertising

Hi-Fi Corporation Vanderbijlpark advertises valid from 28 March till 7 April to sell a 2.1 LG Soundbar SJ-4 for R2699.00.On 31 March I went to buy one. The cashier rang it up for R3499.60 and swiped my card for that amount. When confronted with this the store manager Rhiana admits that the price is different from what was advertised but says that if she changes the price on the system the person who advertised it will loose his job. She refuses to honour the advertised price.