I do think you are able to upgrade your medical plan under the same investment link policy, if it's standalone medical plan, then perhaps you need to buy a new policy.

If you are under Great Eastern, you will be able to upgrade your investment linked policy without buying a new one and there will be a conditional waiting period of 1 month. Which means that anything within the first 30 days you will be able to claim under the old medical benefit. If anything happen after 31 days, then you will claim under the new medical card benefit. That's how Great Eastern repay to the loyal client.
It depends on your current financial status, if you are still able to survive without closing the account and only take out the bonus, I would suggest you to do so.
Take out RM4k from the bonus, ask the company to use the future bonus to pay for your premium and you should able to enjoy more bonuses in the future.
If you are not paying, the company will still declare bonus to you, and your policy will use the bonus to pay for the insurance premium. Of course the maturity benefit might not be RM150,000 at 55 years old but it's still a big amount considering you are not paying the premium.
Ok,Im understand.