I agreed with what other members are saying. Make an appointment with your SA, turn up at the store and find a chair to sit down. Start going thru your wishlist (it helps if u also jot down the product code) and the SA will check via her phone. Then wait to see if you hear her/him says to any items on the list, wait a moment, I will go and check and leave you to go to the storeroom. Usually/hopefully she will come back with something from your list. All the best inventory are kept behind. So its shopping via on the chair.
Add: Way back in the beginning, at first my SA will still reply me yes/no availability. But then she stopped replying. I also thought my SA is giving me the cold shoulder. Turns out they are really swamped with old and new customers. When they are not serving customers with appointments, they have to serve walk-ins. At times I have like 4-5pm+ appointment. Sometimes I text to say I will be late and her reply back to me is, ok I go eat first. So until that time, imagine she still didnt have her lunch yet. (I know its not an early dinner because that day my SA knock off around 7pm.) So dont think too much about her/him lack of response.