did you dial ##000000 with the radio off? This brings up a screen where you can change the number. I believe you only change the first line then the phone will want to restart. Let it and you're number should be up there now instead of the other.
My sim phone number isn't my cell phone number. It's a completely different number and a lot longer than my cell number. To OP yes dial that number with the radio off and you will get to a screen. Change the first line to your cell phone number, save, and restart your phone. You're number should be there instead of the other number.
Oh, but it shouldn't affect your phone number should it? I don't understand the sim cards very well, I just know that my sim number is completely different from my phone number and I've read that if your phone number isn't in the my number section you should change it by the ##000000 option lol. The more I'm in this thread, the more I get confused lol