My only shift this week was just wrong apparently

My manager knows I’m trying to save money for uni and I’ve told them I’m hoping for like 20-25 hours a week, yet this week I was given one shift which has now turned to no shifts.

I have worked at this store for around 4 years which is longer than most other people (the store opened 5 years ago) and I’ve even worked as a manager myself for a while (I gave up the position due to stress at the time) so I would say I am one of the better workers.

The store has been doing pretty bad recently tbh but instead of laying off the employees that don’t know how to do their job properly, they just give everyone 1-2 shifts a week (or in my case, none). I’m currently trying my best to search for a new place to work because this is just not gonna work anymore.