Terrible service. Called for parts at 4:44 when al...

Terrible service. Called for parts at 4:44 when all their signs on the doors and online say they are open until 5 or 6. The switch board lady put me on hold where I sat for 5 minutes before getting in my car and driving there. By the time I got there I had been on hold for 25 minutes. And the parts department was closed. The reason I needed to go there is because the parts person had sold me the wrong thermostat. The Duramax takes two different ones and he sold me two of the same. I'll be buying my oem parts online from now on.