Unreliable Cashier's &bad management

Pick n Pay Boston Bellville is not reliable & you can not trust their employees.I went there on Monday bought a bottle of Leopards leap cabernet sauvognon which costs R65 per bottle & a pack of doritos that cost R16.99 .I had R200 and they gave me R18.00 change and I didn't notice it until I got home.I called the store around 20:00 pm and a lady by the name of Bronwen answered the phone & I explained what happened & she answered the phone told her what happened she took my number advise she will contact me but she still hasn't .They owe me R100 change.I eent back there again today spoke to their manager Steven whi clearly didnt want to hear it ,told me they were not over with any money over than R20.00 .Asked him to check the Camera's told me its a waste of his time to check Cameras between 19:00 to 20:00 pm .I'm so disappointed with this store and thr treatment I got from the manager.