To preface - I work in an office doing non important stuff
My usual working shifts are Mon, Tues, Thurs, Fri (my usual working from home day is Thurs). My manager dropped on me last second as they were walking out the door today, a Friday afternoon that my following weeks wfh day cant go ahead due to staffing numbers as "we're not allowed" to leave 1 person in office (which we have all been left solo in office multiple times enough times). My manager has said I cant wfh any other day next week and would have to do all 4 days in office, and believes she has given me "enough notice". As part of my occupational health adjustments, I'm allowed to call into work in the mornings if I'm having a day where I'm overwhelmed and may need to wfh that day.
Can I stand my ground that my usual routine is wfh Thurs or can they pull the 'business needs' card and take away from me? It isnt written down anywhere that Thursday is MY day, just that I have a wfh day per week.