From my experience, if you had them on an old phone you can send them to a PC via the bluetooth as a .vcf file, then you can send it to your new phone as a .vcf file and it will automatically put it in your contacts. Not sure if it has to be the same phone but I would guess that it would inter changable.
I've also used googlesync app, but it doesn't import. Its good for getting contacts off a phone though.
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