I haven’t missed an invoice before, but I have bought my 2020 GMC Sierra 3500HD AT4 Duramax through PartridgeAutoSupply.com. Support was one of the best parts of my experience. I’d send an email and call them today. If you’re within driving distance, I’d personally go to 613 N Meridian Rd, Newton, KS 67114 and talk with someone in person. I’m sure they’ll explain what your options are.