FORD LOADBODY CANT SUPPORT A FITTED TOOLBOX

Our company bought 4xFord Bakkies in 2 years. 3 of the 2.2 XL HR are used as site vehicles (2x2014 & 1x2015 model) have been fitted with a toolbox designed, built & fitted by a engineer to ensure that the weight distribution is installed correctly as Ford hasn't got an approved toolbox to offer.The weight of toolbox is 22kg complete & then tools are loaded into it which tops the scaled at no more than 40kg.The 1 2.2 XL HR loadbody has started to tear on the corner seam slightly. Ford has stated that this is due to the toolbox fitment being incorrect.I have asked for the correct fitment which I was advised would be sent to me as we want to be compliant.Ford has said that we have lost our load body warrantee.I am still waiting on the details of how to meet their standard requirement for fitting to keep our other 2 in warrantee as this is why we bought new vehicles.It shocks me that we have to beg as a client ... Ford has Eskom as a client & they have made detailed instructions for them as they would loose the contract with Eskom. Ford doesn't care about the smaller clients. I can assure you this will be the last Ford we purchase as this is not the only issue we have experienced.