Aiyo, I understand your frustration lah! My friend actually sees Dr Lee Jiah Min at KKH and she says the doctor is very pleasant and patient, will explain everything in detail, especially since my friend is high risk and needs a C-sect, so she appreciates that a lot. But ya, someone in my mums WhatsApp group mentioned that Dr Lee is quite strict when it comes to giving MCs or memos, she goes by medical necessity, so if there's no clinical reason, she won't simply anyhow write one for you, which I think is why you kena turned down lor. Some mums love her for being thorough and honest, but a few did say she's not the type to just give you whatever you ask for lah.
Hmm I haven't seen her personally but I think most KKH doctors are quite strict about giving HL or memos unless there's a clear medical reason — they don't just give it on request lah. Maybe you can try explaining your symptoms in more detail during your next visit, sometimes they're more willing if you describe how you're feeling day to day. Hope you get the support you need soon!