I have had a shop cancelled by Ellis for the same reason, FLG8ORS. I had signed up as a back-up shopper for a shop, was eventually promoted to primary shopper, and shortly after that, the shop was cancelled to allow the original primary shopper to enter their report. I have also had a shop rejected with pay from Goodwin. They over scheduled and another shopper completed the same restaurant shop on the same day as I. My report was not used, but I received my full payment and reimbursement. I was also asked to return to the restaurant to complete the shop again the next day. Too bad I was unable to add the shop to my schedule as I LOVE the food at that restaurant! I was impressed with Goodwin! They actually called me on the telephone to inform me of their scheduling error.
I have also had a video shop cancelled by Ellis with the excuse that the shop had been cancelled by the client. Based on their job board, and my experience with Ellis, the truth was actually that they found a shopper with their own video equipment to complete the shop. The shop was back on the job board with a small bonus, but I could only self-assign as the back-up shopper. I won't ever have that happen again now that I own my own video equipment! Oh yeah, give me that extra money because I don't need video equipment mailed to me! LOL!
I hope your evening worked out for you, FLG8ORS!