Gardenline twin hose irrigation timer?

i bought gardenline twin hose irrigation timer from Aldi
last year. The large plastic nut from the timer which connects to the hose union bib tap has started to split on the bottom of the nut which is attached to the timer and
is leaking, at some stage this will pull of the timer i need
a replacement nut to fit onto the timer can you help

patrick quinn
February 2012