With reference to the 1st October, if you take a look at the government document the first line says "From the 1st October 2012 a private club....." thats where the date reference came from.
Rules and legislation have been flying about for many weeks and months, but this is the very latest document and should now get you your discount back.......hopefully.
Interesting that your club had already removed age discrimination subscription reductions before the government ruling was made legal....might also be a point of law for you to go back on?
Good luck