I also did not get paid for a Morton's shop, not telephone but a bar shop. The scheduler conducted a telephone training and told me to identify the manager. The manager never entered the bar and I was not instructed to specifically ask for the manager. When I submitted the report I wrote that the manager did not enter the bar. I was not paid for failure to identify the manager.
I have been mystery shopping for quite a few years and this was the only time I was not paid. Since I really did not follow the directions I decided not to pursue it, and instead accepted it as an enjoyable evening out.
You might want to contact Shannon S. to discuss it if the same company. Whenever I have contacted her she has agreed with my concerns. My husband, who also shops, casually mentioned the Morton's lack of payment the following year when he was discussing something else with her. She said I should have called her at the time.
I have found Shannon to be very fair when I have contacted her with concerns about inferior quality editing. If you think it worth the effort, I would call to discuss with her.