I was switched to Lanter about 5 years ago. The first 3 of which we deplorable. Had a meeting with GM and Lanter managers over the horrid service. It came to a head when a driver wadded up my return paperwork and threw into a tote. The Lanter officials blamed it on rain. Funny, we had no rain, didn't know water could shape paper into a ball, and put said ball in a completely dry tote. After that meeting, service has been much better. I do have the Lanter regional manager on speed dial and when I call, he does jump through hoops now.
They still have the occasional sh!t show. They often have to go get a box truck for my returns. Most of their deliveries are done by van or pick up with a shell on it.

Just last month, when the driver did have a box truck, he forgot to close the door on the back and littered the highway with my parts. Sadly, this is what GM gives its best customers.