Disrespectful Manager and Cashier

My wife an I went shopping yesyerday for sunday Lunch and also bought some stuff for the month... We took the special for potatoes and carrots and onions and tomatoes for R125.00 I think... While getting everything we could get the 2kg tomatoes so just took 2x1 kg packs instead went to pay and the cashier (Lindokuhle with no name tag on) said we are not allowed to do that My wife the said can i speak to the manager and also the same problem name tag is turned around in her shirt no name(Mpho) expalined ouer situation and she said that it was not her problem and she doesnt stock the shelves or the stoor .... Its very bad customer service If you can threat people they way they do I then just said calmly that i will phone the Regional Manger on monday morning and she just rep**** with "Do what you want " and kept on talking to the cashier in her Language