All you need to do is call up the company that your phone is locked to and ask them to give you the unlock code, and they'll ask you for the IMEI and they may also ask for your full name and email. Personally, I refuse to do this unless I have to, so I give my first name only.
As it happens, I unlocked my Huawei phone a day or so ago and it was with Bell, the online rep wanted to know everything I mentioned above and said if it makes me more comfortable I can call, so I called Bell (not due to comfortability but because the rep was irritating me, not her fault, she only reads a script), and the guy on the phone wanted the same details. I gave him my name and then he asked for my email to get the code, I said I could just write the code down on my computer and he skeptically said "ok".
I popped my PM sim card into the phone and used the code, and it was then unlocked.
