How do I restore my BBM messages?

I used to use an android before and I did click on "save chat history", I thought when changing to my IPhone that when id download BBM on my IPhone and sign in it'll automatically send all the BBM data through, I was partially correct as my contact went through and that's about it. I want to know why didn't my messages go through even though I clicked "save chat history". Is there anyway I could get my messages back onto the IPhone?
I did have all the conversations on my previous phone, which was an android. As I have switched phones, they are no longer on my android: neither did they go through to the IPhone. Could you please answer me, thanks.

The chats are saved on device and not synced to the BBID. Hence, you will be unable to retrieve your chat history.

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