All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Since the points are given in return for using the credit, then it is not permissible for you to use these points without seeking the permission of its owners because the fact that the phone numbers are registered in your name does not make it permissible for you to dispose of the points that are given to these people in return for the credit which they used.
However, if they give you permission to do so, then it is permissible otherwise it is not.
Allaah Knows best.