Full-time to part-time work.

Hi guys,
Not sure is this the most appropriate section on the fourms but I hope you can help.
I currently finished by year1 in busniess magnament, I did ok passed my year which I am very happy about sense not been in formal education sense 2010.

My question today is and hopefully someone can help.
I currently, working for a bank as a customer advocate, which is my main working experience, so I find it easy enough. At my initial interview, I explained to my interviewer , that I maybe going back to university next year depending on results (what the interviewer said to me yah that's fine you can change your hours accordingly when its time to go back to university.) This was one of my main catalyst in taking the role there.
Sense joining the job 4 weeks ago I told them form day1 , I am attending university again in September , they are now making it extremely difficult, in changing my hours they first told me that I gotta wait to August and resource planning deciced if the busniess needs hours change. Unfortunately, I cannot wait to then as I am originally form the republic of ireland and I am clasifed as a EU migrant and I need to be working part-time hours comes September for me to able to get maintenance loan and dsa.
They know want to do a opp health report to see what adjustments can me made in work.
That's ok its in their duty of care to do this.
But ,unfortunately, I cannot wait much longer as everyone knows student finance can take awhile to process.
I want my payments and dsa be sorted or nearlly sorted before i go back.
I am become more more frustrated with everything and there putting my future at risk.
Any advice would ve greatly appreciated.
Thanks.