Need advice on my 401K error issue. Thanks

My company messed up my 401K. They transferred wrong number of shares . So they owed me 3000 shares of company stock, but they tried to pick a date which stock hits low end and return the money($70000). When I questioned this, they said they will review the case and waited almost 180 days . By the the end of 180 days, the company stock moved even lower. So they only returned $30000. and they claimed they r doing it by the law. Anyway that I can argue about that ? Thanks.