Appointment for a seat problem that no longer open...

Appointment for a seat problem that no longer opens (rear) the night before send me a message with written appear at 10.00.
Arriving at 9.40 am hoping to leave the car early. At 10.45 am I go away disconsolate after having lost half a morning just to leave the car! 1 hour wait and it was not my turn! Leave the car in three minutes in a workshop !! get down!