Fed Ex Ground Shipping Woes

I've had two situations over the past 3 months where FedEx has caused shipping damange. I have had zero prior issues with them in the last 4 years. They immediately rejected the claim on the first item (packed in the OEM Box with original packaging materials and cited "insufficient packaging."

I learned quickly and recently had a seller professionally package an amp that was being shipped to me. The professional packer used a double-boxing system with at least 4 inches of rigid foam and Styrofoam peanuts. Shippers typically require a minimum of 3 inches of insulation around the unit.

To make a long story short, FedEx managed to managle the outer shipping container, mangle the inner shipping container, and damage the unit.

I'm at a loss for words......

Has anybody had better luck with one of the other couriers or any tips? I thought that both the seller and I did everything humanly possible to ensure safe delivery.