How to change phone number?

im using the instinct on the cricket network and when the guy flashed it, it some how put the wrong last number in the phone number in the phone.so when i call my voice mail using the voicemail icon it calls some lady as the number in genarel settings phone information the phone number is wrong by one number is there a way to fix this?

ok i fixed this i searched thru google and found this code ##000000# and it allowed me to put my real phone number.