Best is you contact CS and Sales dept a few times to ask about it. See what sorts of answers you get. Not sure which package you referring to. You can read previous Oct posts where there have been lots of comments and user feedback. And make your own decision.

Added:
Can you post the PDF or link to it listed on your 500M redeem page? Or point out the section jackbanner is referring to?

I still don't see what jackbanner  is referring to saying price will be RM199 for 100M.
Added:

And Ronin_Amin , you have also mentioned RM199 in post #6133. Where do you get that info?

Those are the plans offered to new users. There are no 500M and 800M plans at the moment. Your 500M plan is as an existing user.  Existing users are eligible.

On that page you linked, scroll right down and read the FAQ. Take note of #19 especially. Be aware the new 2 year contract terms have changed for termination penalty, ie you have to pay remaining month fees if you terminate early. Its somewhere in the FAQ or T&C.

On the page you linked, scroll up a bit to the "Existing Customer" section and click the "Via Self-Care" button. Login into your Unifi account. You should see the "redeem" page. See what you have there. It should only show your current package.

Some 500M and 800M users have done the redeem as posted in this thread. You can read through the posts from 01 Oct onwards where all this has been discussed. You can also compare your 500M package price with others. Not sure what you are paying now. If its much higher than others, than you may want to see what you should do next, or you'll be stuck with higher price with the new contract.

You can also call CS and give them your account info and ask them exactly what will happen to your package and price in Jan 2020.

Kindly get all the necessary info before making your decision.

Added:
Although those are the plans offered to new users, it is also possible for existing users to change to one of those plans if they want. But that is chaning / switching plan, not redeeming / renewing their existing plan. There is a difference.

Hopefully you didn't get the same CS giving the same answer...

Can you share your 500M package price and discount as shown in previous bill without personal details? Its ok if you don't want to. If you do YEP, check dashboard details especially discount before and after YEP.

Please clarify. You say RM169, but RM99 + 60 = RM159.
If your discount is now RM130, see after YEP is activated whether it changes to RM150 or not. Perpetual means as long as you are subscribe to your package. Not like some where discount is valid for 24 months.