How to change new sim number
 

Dear friends,
I had activated cdma in lg fathom, it was working fine. But I want to change cdma sim number to another sim number.
So I went to rim webworld and changed the existing sim number and told to punch the another working sim number against my meid number of the set . He did So. But now it is not working, it says your phone could not be activated.
Please help where I am working.