Call Customer Services on 0860 576 576, request to stop the card. You can then get a new card in store. The store doesn’t have to be the one where you collected your lost/stolen card in but it does need to be the same brand.
Example: You signed up/ account approved in Foschini Canal Walk. Your nearest mall is now Fourways. You would need to get your replacement card from Foschini in Fourways. You cannot get your replacement from Markham in Fourways. You may still shop across all TFG brands.