Where can I re-register my sim and also get a sim swap

Hi Adewale, you can visit MTN Service Center, 30, Ojo Alaba international, Alaba.

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/