unsociable hours working?

I was reading a PDF document by USDAW
and it stated that times after 8pm are considered unsociable hours

My shift is 7pm till 10pm meaning 2 of my hours are unsociable
which is over the "50 : 50 rule"

would that mean, I should be paid 1.3x minimum my hourly wage? 

I also worked 
9pm until 1am last week (wednesday.)
and only got 1 hour at 1.3x

(i only work little hours as I am 17 in college, so dont have time to work fulltime with fulltime college.)

It doesn't particularly bother me, I am just wondering.