I’m also a little surprised that the new SA let the old SA know AND that the old SA told you all about it! Maybe they know each other and the new SA doesn’t want to step on the old one’s toes, especially if they are not sure whether you are going to completely switch or if you are just trying to get a Lindy and go back to old store? In any case, I don’t like how your old SA *told* you about it. Like some sort of “I know what you are trying to do...”. I guess given that there can be competition and cliques among SAs within the same store, maybe such things also exist between stores in the same city/close to each other...just like any other workplace...
I think it’s impossible to know exactly why one of them found the bag easier than the other, too many possibilities we will never know about...could be simple luck and timing and shipment arrival happened to work out, could be due to where the SAs happen to be at for their sales target, could be whether or not they have other clients asking for the same bag at this time, and maybe the new SA just tried extra hard to come through for you with the belief that this may help make you switch to them (complete guess obviously)...
Long digression aside, I think if I were you I would decide my next steps based on where my “sunken cost” so to speak stands with the old SA. For example, if I’m waiting for a bag offer and have already spent a healthy amount without seeing it, I would stick around a bit longer, remind them of my bag wishlist, and at the same time be very cautious about any further spending with them. Then see if the bag offer comes & re-evaluate based on how that worked out. If on the other hand there isn’t much spending with the old SA, I would make the switch.
In any case I would have a very firm and honest conversation with the old SA when I go in for that appointment. Obviously be polite and respectful, but I wouldn’t be scared to be direct and open about my frustrations and remind her of my wishlist and ask for expectations. If she continues to give me a run around and say oh it’s too difficult & some very vague and long time frame...I would likely switch to the new SA after this appointment. If she promises to try hard and come through and give me a resonanable timeline (like end of this year, December tends to be a month with more bags), give them a little bit more time and one more chance to see what happens.
Bestest of luck to you. Hope to hear a happy update some time!