How can i reset the email and password registered in my magicjack?

the magicjack we have is just given by our relative form the US (we are in the phil), we have used the magicjack once when we give it a try, but when we want to use it again, you have to log in with the email and a password. we asked our relative who gave it but forgot the email used... we tried all their email but "email was not found". how can i re-register the magicjack with my email so i can use it agian?