FBA Shipment To BNA6, Delivered, still not Checked In, No support available for sellers, Amazon doesn't follow its own policies

FBA Shipment To BNA6, Delivered, still not Checked In, it is Small-parcel shipments according to Amazon policy "Small-parcel shipments can take up to 4 days to move to Checked in status." but its more than 4 days no seller support for FBA shipments, No one to address FBA issues, they just says due to heavy load, its delayed, products running out of stock, inventory from inbound gets lost or damaged.

We sellers can not open case for shipments not checked In, no Support for sellers,

Moderators please Help sellers !!!