Registering t mobile phone on Rogers network

[zap16]

I have a unlocked 8220 that comes up T-mobile on the screen that I'm trying to register with the Rogers network so I can get my rogers.blackberry email to work. I have spoken to Rogers 4 times now and they are able to get my phone registered on their network and send me a test email and all works but then a few minutes later it doesn't again. I spoke to them tonight and they stated its only because the phone is only "partly" unlocked. If that makes sense. They told me to get a unlock code or call T mobile which I did and they stated they will not give me a code or release the IMEI from their network as I'm not the original owner. My question is is it just a matter of getting a new unlock code fully unlock my phone or is it something I have no control of because T mobile won't help me out. I did go into my SIM card and put in I mepp (i beleive) and all says disabled. If there are any suggestions that would be great.