Shocking customer service at payment counter

I'm a regular monthly if not weekly shopper at Clicks spending up to R400 to R500 a time. I was standing the queue with many others, it was fairly that day. The automated calling system which tells the next cusotmer which teller to proceed too had called out teller 9. I approached teller9 only to find customers still paying and unpacking their items, so the button was pressed prematurely or incorrectly - nothing wrong there, we all make mistakes. <br> <br> I backed up again so I could stand at the front of the queue to wait for the next available teller as I was next in line. The automated message called out teller 6. I approached teller 6 and started to unpack my goods along with my 2 small children... only to be pushed out of the way by the customer who was standing behind me (she was after me in the queue). I asked her why she was doing that and she said that my teller is no 9 and I must go there. <br> <br> I very nicely showed her and the cashier that it was full and still occupied. She, as well as the cashier told me to wait. They ignored me and continued to ring up her items as if I was not even there. Most of my items are now standing on the counter.