First question, what is your medical card? You can check in the attachment on that page.

Could be just could due to coinside or combination of medical inflation rise PLUS your age moved your premium to pay bracket to a more costlier rate.
( check you policy for the table to see if your age had "upgraded" to a next age grouping?)

From what I know, the quantum of increase for SmartMedic is 50% this time. In comparison, the quantum of increase for SmartMedic Xtra (which was launched after SmartMedic) is around 30%.

As to why the discrepancy, refer to the diagram in my first post. Your plan is older, hence it has more "bad risk". The average age would also be higher since it had closed to business earlier, and the healthier ones would've moved on to the newer (i.e. cheaper) plans.

Generally, if you are healthy and have nothing wrong with your health, you should move to the newest plan, SmartMedic Shield. The medical plan's cost of insurance will be significantly lower and the benefits will be significantly better. Plus, with a deductible of RM300, the expectation is medical claims experience will be somewhat better contained.

Can you share the quantum of increase from the PDF? At the bottom, they also share the % value in increase.

How many repricing have you experienced? Any chance you can share the latest repriced rates table?

In any case, if you have pre-existing, you have 2 options:

1) Play it safe and maintain existing cover. Will be more expensive (and exponentially so as you get older as more and more repricings are done), but you will have certainty of cover.
2) Upgrade the medical plan with clearly disclosing your pre-existing. At this point, pre-existing illnesses will not be covered but at least your premiums will be lower.

Under no circumstance should you upgrade your plan or buy a new plan without disclosing your pre-existing conditions, that's going to be a tough lesson to learn when they terminate your policy due to non-disclosure.