Thank you for the link. Accepted answer. It says the hours are: Mon - Fri, 9:00 - 17:30 . Sat, 9:00 - 14:00.
However, it is very poor form indeed for the automated voice menu on that number to just hang up with out providing a reason. It certainly would have been possible to say: "Sorry, this helpline not open today. Our hours of service are: Mon - Fri, 9:00 - 17:30 . Sat, 9:00 - 14:00."