Unfortunately if your MP stats have been altered you can not fix them.
I am going to take a wild guess and say WaW?, if that's the case the only choice at present is to make a new account. You can still play MP and zombies if you are invited to a game though but you will never be able to regain a rank.
As far as LB's are concerned that would be up to the game developers, but from my experience of seeing other people with similar issues they do not do anything about LB's.
But that said you could try asking the game developers about it..
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