Just call to your previously owned number and see if its available or not for your onwards action.
Your post everywhere 😅, if I were you, I will subscribe to the RM98 plan (to get back number), immediately after getting it, MNP to other telco. If successful, congrats. If not successful, let go the number, at least you tried your luck. What maxshit told you might be just to create a deterrent effect.. coz everyone heard the heavy commitment also sienzz liao ..

You can just terminate when you don't require the service, but I believe terminating you may need to visit the centre again.  I will advise you to check with the personnel attending you and be utmost sure there is no hidden terms such as bind you x months when you sign up for the rm98 plan. I was told bind x months is applicable for contract to get free phone.