After what LG wrote on their Facebook page, I'm fairly certain that they are the ones who decided not to transfer the user data. I don't think that trying to convince Gameforge of a data transfer will result in anything. LG are the ones blocking them and what should Gameforge's interest be to convince LG otherwise? There is no incentive for them. Also, since they are used to migrating account data from other publishers, I'm certain that performing a migration would not have been too difficult for them and that it is indeed LG who is blocking the migration (and as I said before - LG said so themselves).
Which means: you, or rather we, need to convince LG somehow that a data transfer is beneficial to them and is worth the effort and money that they would have to put into it. And they won't read this forum so it would have to be on Facebook or their forum, if they have one.