Well, my account seems to be savings max account. Thanks to the above answer from another thread, I confirmed it by going to the 'Change account type' link on the HDFC website he quoted (the website is useful for many online service requests without visiting the branch).
It redirects you to the HDFC instaservices page. And after login through mobile number/OTP, it shows up like this for me:
View attachment 46243
But I don't seem to understand why the platinum DC still shows up with annual charges for me?!
🤔