Did you mean, you want to keep your current phone number?  You can keep your current phone number. You don't have to cancel the landline, if you dont want to. You just need to add unifi, that comes with its own voip phone which you can choose not to use it.  That means you will have two separate bills. One bill is your current landline phone bills. Another bill is unifi bill (this bills will include internet + voip phone charges, if you use the phone).

Your 4M is RM120? Not RM130? What is the package name? How did you upgrade? Did they call with an offer?