Poor customer service from a supervisor

The branch in Northgate Mall ,the service is horrible i went to do my shopping as usual i requested a cashback of R3000 and the cashier told me she doesnt have I asked her to find it she looked for a supervisor a lady short and dark complection ,the time was just after 11 or just before 11 am. she told me they do not have cash its too early for them to have cash I had a full trolley of groceries which amounted to R2100 and few rands - I told the lady that I was coming from the bank I didnt withdraw because i knew I was gonna do my groceries at picknpay where i can swipe my nedbank card pay for my groceries and get the cash at the same time on one transaction and also swipe my smart card but i couldnt I had to go do my groceries else where where I was appreciated as a customer. My problem is that in such a big shop at that time the shop didnt have a lousy R3000 or the cash back is not allowed any more?or its allowed to certain customers. The experience i recieved at the chemist is far great compared to what i recieved at the tills,the manageres was great she fully explained to me how to apply the blister ointment, and her cashier was also great and fast .