CAS issue

I applied for course for global business management with foundation year in london campus i have completed all the condition i got message in CAS shield that CAS issued but then suddenly after sometime go an email from uni that cas deadline has been lapsed for jan intake 2024 and now you have two option either we will defer u to next intake or we can offer you BA(hons) Business management with foundation year in main campus for this intake . I reply with an email that i am okay with that too as now i have no other option . I am in so much stress they not even helping me i am left with less days to apply for visa . Also the staff os not co operative they just wasting time what can i do ? Also when is the last day that they issue CAS so much worried i am