From Facebook to King.com account

Hello, I have a problem. I'm on level 6348 in Candy Crush Saga. The game progress is synchronized with Facebook. Now I want to delete Facebook, but of course save my game progress. I registered on King.com. Then, as per the instructions, I first logged out of Facebook and then logged back in with my King account. But the game progress was not synchronized. I've now played a few levels (15), and now it only saves the levels I've just played on my King account. I've at least managed to log back in to Facebook, and I'm back on level 6348, but every time I log off Facebook and log back in to King, I end up back on level 15. Is there a solution to this? Thanks!