I was collecting a friends caravan from a dealer in Rushden, Northamptonshire, and noticed someone collecting a new van, I pointed out to them that their towball was not an Alko compatable one to their new van, they queried this with the handover person, who said it was. I then spent about 30 minutes with them pointing out the differences. The dealer changed the tow ball for just the cost of the towball , no labour cost.
Very bad service, at that time , maybe 5, years ago.