Besides the BBB how do you fight claim resolution against FedEx

BBB puts complaint for 36 months. It won’t help to resolve anything. FedEx does not really care about BBB as well as the rest of large companies. Normally they require packaging safe enough to drop from the flying by airplane to the concrete ground. Otherwise, better not ship at all or small claims court

I will try that next.  Thanks.

An issue with hard foam is that it is sacrificial. It does absorb the force of an impact but in doing that is crushed, losing effectiveness in the case of any subsequent impact. I've found high-density but resilient foam to be more effective than rigid foam.

The only time you might have a case with Fed Ex is if you used the factory shipping box and system as they are designed to handle shipping stress. Not 100% foolproof, but you’ll be in a better position. Rarely will any of the big companies pay out a claim if something was packed “unprofessionally”.

Your only protection is a packaging that can withstand multiple drops. I found freight shipping on a pallet to be much better alternative for subs, speakers and sensitive electronics.