Dischem robbing us costomer of our purchases

Dischem SA has advertised Daipers (huggies brand) on sale for R179 and on the check out the it was R179 for 2 pack we paid for the Daipers but now we get emails saying that the Daipers huggies brand was a mistake and they will have to refund some costomers of wich some costomers did get thier orders on delivery and collection dischem nelspruit refused us of collecting our orders as a costomer please assist this is my number *** I am in nelspruit