anand1 they got them back because they knew where those shares were and they knew the holder was willing to give them back. The remaining shares are a much different story requiring litigation.
In other words, the billions of shares they seek require forensic accounting and lawsuits which are costly and lengthy. $250,000 funding for such actions costs 2.5 billion shares that will become unrestricted long before the litigation ends.
In other words it is highly likely that the shares will never be recovered and 2.5 billion additional shares will hit the market before any litigation judgements.