This phone has been locked to a network... Is this something that has just happened or are you trying to get this phone onto a different network?
If changing networks where/how did you get the unlock code?
So the phone was on Cellservice and you got the unlock code from them?
Did someone try multiple other codes before you got the one from Cellservice and lock the phone totally? Try putting a Cellservice SIM back into the phone, it may be the only way to get the phone unlocked for now then try the SIM unlock again...
Then either the phone is completely locked and can only be unlocked by the manufacturer or the phone is faulty... Either way the phone will need to be returned to the manufacturer, you may need a proof of ownership... You could try rooting the phone which defaults it but this may well brick the phone completely...