Rubber feet on bottom of case break through siding of case - T.Z. Case ProEdge Series Hexagon Frame Design Double Rifle Case 53x15x4.25, Silver HX0053BS

I have used this case for 2 hunting seasons to carry two rifles. The case has protected the rifles, but I am unhappy with the case siding strength. The case has been transported in back seat of my crew cab with moderate weight on top (another 2 rifle gun case, duffle bag of clothes for a 10 day hunting trip). Of the four rubber feet to support the case (4 rubber feet plus the roller wheels hold the case up when laid down to open) 1 came off and 2 broke through the siding puncturing the pressboard siding. Seriously, this case has had minimal use and has not been mishandled; so the case siding should not have broken.