How to change plan to 99 plan for existing customer

[Zed1]

I would like to downgrade my plan to 99 plan

[remstr]

Hi @Zed1 ,

What is your plan right now?

[Zed1]

Hi thank you for reply. My current plan is rm79 unlimited plan

[remstr]

Hi @Zed1 ,

Then right now you want to downgrade your plan into 59?

[Zed1]

Ya