PACCAR Inc. Customer Service Issues

Our company recently bought six new Kenworth T680 trucks, with three having MX13 engines and three equipped with MX11 engines, all with automatic transmission. Unfortunately, we've been facing issues with the MX13 engines due to faulty fuel injectors. We have detailed documentation of our units' repair history. One truck has been at the dealership since May 19, [redacted], waiting for replacement injectors and new injector lines (part# [redacted]PE or [redacted]PE). Despite significant spending on fuel treatment, we still had to get them flushed by the dealerships. We were promised reimbursement by PACCAR for some of the fuel treatment costs, but the process remains unclear to us. With multiple days of downtime, we are eagerly waiting for the availability of the injector lines and guidance on how to claim the reimbursement. Any help or information on this matter would be greatly appreciated. Thank you for your assistance!