Hi, BB8520, got unlock code, mped page was already showing 'Disabled' so I couldn't enter anything.

The instructions with the unlock code said this meant it was already unlocked. I put my payg Virgin SIM in and it shows network and signal bars but when making a call it shows 'Authorisation Failure'. It will not recieve calls either (just rings out with on landline with no sound on BB 8520) no texts or WEB access. All apps- calendarnotes etc working perfectly. I was on the phone with Virgin for an hour last night and they couldn't help. I did a Security Wipe and rebooted it at least four times during the contact with Virgin. The Sim card works in another BB, I was given this 8520 as an upgrade.