For this ticket, after a few weeks wait, we received the refund notice email and PDF on 30 Oct and the fare and taxes + fees hit the credit card about 7-8 days later.

Overall, everything I had to claim so far has been processed by SIA without much arguments even though some items required additional explanations and a few follow ups and tracking. A pretty decent overall performance in our experience compared to other carriers we had to deal with with a "medium- to low" hassle factor. Not perfect, but far from terrible though I can see how inexperienced travellers may struggle and feel overburdened. YMMV.