Our booking had mistakenly had 1 am return which should have been 1 pm which was still within the 24 hour rental period as the car was picked up at 6 pm.
We pointed this out at pick up and the man processing the rental said nothing could be done to change it.
We emailed Goldcar with no response and then phoned them and the very polite lady said there was nothing she could do and that we would have to return to the office where we picked up the car. This involved driving an additional 2 hrs to be told the rental could not be changed and we had to make a new rental and get a different car.
Crazy situation that this could not have been changed when we first rented the car or by email, internet or telephone. Wasted half a day on a trivial matter.