Service department called to have a window seal re...

Service department called to have a window seal repaired on my van the service department transferred me to parts who said yes we have 2 in stock I said I would like to schedule to have one installed they said ok transfered me back to service who scheduled me an appointment to have it done the following week I took a half day off work drove the 40 miles up there to be told now they don't have my part I feel this is very poor management. I will NEVER go there again this is a good reason to drive to a better Dealership