How do I retrieve my lost sim. My brother name is showing when I went for replacement

Hi Aderant. MTN usually assume that the person that registered a line is the owner of the line. It will be assumed that the line belongs to your brother. You need to visit MTN office with your brother, he will sign a consent form that the line belongs to you before the line can be registered in your name to enable retrieve it.

You can dial *123*7*1# to get information on the location of any of their shop closer to you.
When you dial the code, you will be required to enter your State, then your Local Government Area, you will receive SMS on the nearest MTN office address in your location, or you can use this link: https://www.mtnonline.com/personal/find-a-store/