You can disable your Master number as follows.

• in SkyPhone > "Point-Paid Calls (for Masters)" > "Disable Master Number" > Tap "Disable Master Number."

Note: If you disable your number, it will be unavailable until you enable the number again and the "Points" icon in the tab bar will disappear.
Note: When you enable your Master number again, your registered info and your earned points are kept the same as before.