Manager/HR scam

I am asking for WFH for one month on medical conditions HR approved documents now she is asking to take approval from gl and supervisor when i talked to supervisor he asked to take approval from gl . Gl is saying will provide WFH but you need to work 9 to 12 on week days and every Saturday . If you are ready for this please drop a mail to me stating same othervise no WFH . I told HR same that manager is forcing to work 12+ hours and on weekends she simply said it is on basis of business requirements i can not help in this. She said to take LWP if u have health problem and then come back . Can i ask for release from project in this situation and will it be possible. Plz help !!!