I've been trying literally every possible thing. I'm at Day 58 by now and I still can't get the stupid store opened. I've finished all of Sarah's seemingly automatic quests and have Elsa's cafeteria stuff done (or at least I'm hoping, cuz I've been drinking coffee there 3 times a day for the previous 4 days and nothing) and I can't talk to Stella cuz she keeps telling me about the sisters thing and then running off for a call.