Fuming!!

Just phoned to update my manager and inform her that my doctor will have a sick certificate ready for me to collect tomorrow and that i will be posting it out to her. She got really arsey saying that it needed to be with her by tomorrow and that they should have it after 5 days and my doctor is wrong not to issue it until ive been off for 7 days. Well in my employee handbook it actually says its required after 8 calendar days so suck on that one!!!!! She is being really difficult with all this and I hate her for it, its just adding to my stress and i don't need her on at me as well!