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do you have a gmail acount syncronised with your device before you updated
try to recover via googlemail when you go into your contacts chocse to recover via email or sync via email you'll get your contacts back
You can't use a backup made on previous android versions, what you can do is sync with google then
phonebook > menu > filter > google/gmail
You can export your contacts to sim card or SD card, just find this option to the menu of Contacts app!