They did get back, and they gave me shifts straight away. There was no excuse given, just the shifts and honestly I don't think I should be asking for explanations at least for the moment. Seems to be a bit of a mix between company policies, not enough HR staff /sloppy HR/ poor communication, and shitty software.

One of the employees told me they went through the exact same experience as me in the beginning, and they've been working there for over a year now. One of the new recruits got shifts two weeks earlier than me but missed the first one because nobody contacted her and the app is glitchy af. So at least it's not personal I guess. Even after getting shifts my schedule would show up blank for me too and one of the managers had to manually override/change things for me to actually see things properly. And that took a day to update. The store itself is chaotic, I've worked retail in the past elsewhere and company management was completely different (much more organised) so yeah.

On the good side, the staff and managers seem friendly not as uptight as in other places. What bothered me wasn't the waiting time but the "probably next week, keep checking your online portal, it's all good" when they know they don't know when my shift is and they also know the app doesn't work well with new recruits. I understand being honest about it on the phone could get people in trouble though so I'm not sure this is something I would have beef over with someone.

In short, it doesn't make the situation any less sucky. The replies here were spot on: Probably poor management + chaos, move on if they don't give you what you want.