Don't feel obligated to keep using a SA just because they helped you once. Until you find a good one who is attentive to your needs, do what you must to get your items, otherwise, you may miss out.
These SAs earn commission on top of their basic pay. So, the commission works on how much product you can sell. The more you sell, the more commission you get.
One SA can be nasty or jealous of another SA because he/she earns more. Sometimes, they may not even pass the message to the SA who you are looking for.
If you don't know this SA very well, just call up the store and speak to anyone. If not, you may miss the item.
My SA gave me her mobile number so I can send her a text at anytime I want and she makes sure that I don't miss any interesting new release.
call and speak to someone available sometimes when you waitlist time is of the essence so you may miss out waiting for this SA to get back to you