Biglew

I purchased a 2013 Chevy Silverado in November 2018 and there was no sign and rust anywhere. I wash my truck a couple times a week and spray out my fender wells and under the trucks as well and just noticed there was a rust hole starting & paint bubbling around the fender wells. I read about the plugs in the fender wells in the previous post so I pulled them and found mud & rust packed in between the fender well and fender of my truck. This is a terrible design and will end up costing me a lot of money & time Im sure. Does anyone know if is there any recourse or warranty GM will honor.