how can i unfreeze and unlock my samsung E420 mobile?

some time ago i purchased samsung lily E420 from ebay. Its in an as new condition but was locked to Orange network in spite of seller saying was unlocked. I should have just asked for refund, but didnt. Needless to say, from my numerous attempts to unlock it with various codes from the internet, it is now frozen. My daughter would love to use phone. Any suggestions please.