If this is similar to the bank shops I do, there's a spot to list with whom you interacted. I'd just list both, and describe both in the applicable question. I also would mention in the narrative portion how long you had to wait to be attended to by the second person. I think that's part of the story they want you to tell. Just state it factually, e.g., "After X minutes, Associate #2 blah, blah, blah." If you think the wait was exceptionally long, I'd note why, if you know. "Associate No. 2 was with another customer, and it was X minutes before he/she etc."
I learn something new every day, but not everyday!
I've learned to never trust spell-check or my phone's auto-fill feature.