Jailbreak gone bad iphone 4

[therealdahl]

Hi. This is my first iphone that i bought of a friend. The Mobile company wont unlock it until they pay what they owe.
Yesterday i tryed to jailbreak with greenpoisOn and now the phone dosent work at all. When the jailbreak was done, the phone turned off and now it`s dead. i now got it running again. How do i now the jailbreak worked ? and how to get it unlocked ?

Please help med

therealdahl