Cashier's bad attitude towards customers

I got the worse customer service ever on Sunday at pick and pay Westgate,

I always do my grocery at pick and pay supermarket , on Sunday I needed to withdraw money, I queued with the rest of the customers, when it was my turn, the cashier asked me if she could assist the two customers behind me, she's got the money in her till, which I agreed upon the completion of the transaction, she told me she's going on lunch, she will try and ask another cashier to assist me in her till, When I got to another till, the cashier was so rude, she told me she's gonna assist me when she's done with the queue, I told her I had already queued, she told me my transaction is gonna slow the line so I should wait, the cashier was so rude that she told me is not her fault that the other cashier could not help me.

I asked for her name since well she wasn't wearing a name tag so I could escalate the issue to the manager, she told me there's nothing you could do, I went to the manager to complain but the cashier was still rude right in front of the manager.