This is what I call a cupboard to the wall moment. How does Lebara come to go to another provider and ask there to make the number active. Just sheer nonsense! You probably haven't used or upgraded your number for a while, and then they close your number. What they do with every provider, by the way, is not new. Always check yourself carefully to keep the number active, that's the only advice at the moment.
Cecilia is right, Vodafone cannot solve this for you either. Once the song has stopped, it has stopped. That's a pity, but if you want to file a complaint about that, you really have to contact Lebara.