What happened to customer service?

Good Day, I must say that am highly disappointed in Omphemetse Modisane, who was our cashier on Monday afternoon. The cashier, seemed restless, impatient and quiet slow. She was working in the 10 / less items till. There were about four customers before me and my partner, and it took us 20-25 minutes before being assisted and all those before us had less than five items each. Then, the lady before us asked this lady if she was a novice , because she was too slow and to my suprise she answered by saying that she was not feeling well. I then asked myself if we deserved to suffer because of her well being? If she was sick as she claimed why did she not report to Management? Well, now can someone please inform me if such behaviour is acceptable? What exactly is customer service? Do we have to be happy that we got served? Do cashiers and others in retail go under any kind of training?