Lost FBA shipment BHX3

We had a shipment delivered to Amazon Fulfilment Centre in Daventry on 16th December. As yet it is still only marked as "Delivered". I have written to SS and they have asked for invoices, which I provided before Christmas. Now they are saying the contents will be in the process of being sent to other FC's. But surely this cannot be the case if it is not checked in.

I pointed this out some 2 weeks ago but SS has still not replied.

Has anyone had similar problems or could advise what to do

Thanks