Bad service

I got the worst service from Shoprite Actonville Benoni I and my colleague went to buy few items and she saw the price for bananas it was 14.99 per kilo but when she weighed them they read 19.99 p/kg we asked for assistance a lady came and she rectified the price she gave my colleague the bananas for 14.99p/kg I also took the same bananas the lady refused and she told me she already changed the price to 19.99p/kg how possible is that.