Woolworths employees not trustworthy

I accompanied my friend to woolworths sammy Marks pretoria.whe wanted a lunchbox bag and for some reason thought it was written R100.She took some few items aswel and went to the till.On getting to the till the lunchbox bag was R150 and the guy said it was ok she can pay R100.That sounded so wierd to me but i just couldnt get in between their issues.The security and the door didnt request for a receipt.On getting back towork i requested if i could check her receipt and boom!!! Surprisingly the lunchbox bag was not there in the receipt.Meaning this guy just pocketed the R100