You're right; they are still being investigated. However it seems fairly clear that there has been some creative accountancy going on with a company that doesn't really exist, so Leicester City are effectively trying to avoid having to pay up.
Forest gambled and had to sell their best players and take COG on loan as a replacement. Fulham and Blackburn aren't having the best of seasons either.
At least they're paying their fine. Amongst all the Leicester loving, it's not being widely reported that they're still trying to avoid paying their fine (from 13/14) due to a dodgy deal between Leicester City and a company that, apart from an address of a small unit at a Sheffield business...