Talking with another lady

This is the second time, I have had a bad experience while shopping at Pick n Pay (Workshop). The packer who was working with Angelina was talking to anther lady and when I have finished paying, I took a plastic to pack my goods and she said in a bad attitude that she is working here why dont I ask for the plastic and I responded that I did not ask because she was talking and she continued to talk , what I dont understand is whether I needed to wait for her why she finished talking before she can pack for me?