I have had many situations like yours too, when I had knowledge from my target that they will not be assisting me when I arrive. While you are right in stating the instructions do not specify for this word for word scenario, we both know that there would have been no way for you to be passed off upon arrival, which was allowed in the instructions, because the 'pass off', already happened over the phone.
When this has happened to me over the phone, where I indeed knew I was going to be passed off, or had a good idea it would happen, because I was talking to a manager and they kept saying: "my staff will be here to assist you", or something similar, I have done a couple of things. Sometimes I try to get their schedule, telling them how comfortable I was with them, and ask if they work everyday or state I would rather speak with them because I hate starting over with someone else, etc. That has worked sometimes and they will say they will be here on this or that day. Other times I have called the office or emailed and told them and they have let me try to pop in on another day when that target answers the phone, so I can try to get them on-site, or get a legitimate pass off. They have added a bonus for the extra time spent to complete the shop. And sometimes the scheduler has just paid me for the telephone call and did not ask me to go.
I think the fact that you knew in advance there was no chance to shop the same person on-site and did not seek advice was it. And there are other general instructions that say we have to try every effort to shop the same person. Knowing already they would not be there means no effort was made at all. I know this does not feel good, but it was a mistake and you will never do it again!