Pick n pay carlton centre cashier attitude

Yesterday I was at pick n pay carlton centre. When I got to the till I asked the cashier (Livhumani)to wipe the roller belt that we put the food through to be scanned . since it was very filthy I was not comfortable to put my food there. She then grabbed the cloth and sanitiser and she took her time wiping the till area (not by the roller belt), removing things and looked at her colluege and started laughing. While I am standing waiting to be helped. I got so angry and went to the other till after that I addressed the matter with the manager "William" called the lady and instead of acknowledging the mistake and apologising, she denied everything. I got even more angry coz when this happened the manager also saw since he was standing right across. The manager said they will take necessary action against her but I am not convinced. She needs to apologise about such childish behavior.