add a new line to my prepaid account keeping the same number

magenta10353141

    So I and my friends took a 4 line prepaid plan a few months back with my name as the primary account holder. Last week, one of my friends moved to another carrier leaving 3 of us in the plan. Now, I have another friend who already has an existing T-mobile prepaid number (not in a family plan) wants to get added to my account so that we can have 4 line plan and save money.

     

    I called customer care a few days back and told about the above scenario. They mentioned that I need to get a new prepaid sim which acts as a temporary number and get it added to that plan. After that, I and my friend can request T-mobile to port my friend's number from his old sim to the new sim. Today, I went to the store, purchased a new sim and called the customer care to change the new sim phone number to my friend's old phone number. They were saying now that it's not possible because we cannot merge rebellion accounts (I don't even know what the rebellion account means). What should I do now? Why did I get false information in the first place that it is doable?

     

    Any help to solve this problem is much appreciated.