401k transfer mapped to same funds

My employer switched 401K providers. The new provider had the same funds I was in. Instead of using the ACATS  To transfer my shares they mapped my funds, sold them off and bought them back the next day. I ended up losing shares because the market went up while I was out.  I've lost about $6000 in the transaction. Do I have a claim to get my shares back?

Not if you received the required Blackout Notice. 

I recieved the black out notice and it said my funds would remain invested during the blackout.

I have never seen a transfer like you are talking about happening as shares vs they are sold at one fund on day 1 and the cash is invested on day 2. 

Nothing they did was unreasonable and is industry norm so I can't imagine a path to legal recourse.  But I am a CPA not a lawyer. 

Thanks.