Pnp false advertising

Pnp William Moffett port elizabeth I purchase 2 x 2ltrs of coke and sprite advertised in catalogue at 30rand for deal When I got home I checked and saw I was charged 40 rand which is false advertising. I contacted pnp helpline or waistline as I submitted all docs required ,till slip and catalogue indicating price and was promised someone would contact me from store,from 19th Feb I am still waiting still no contact Then to add injury to insult I get sent email saying been resolved and how much do I rate their service Well zero is rating as matter has not been resolved very bad service pnp