Leaking Gardenline timer. ?

I have a Gardenline timer that has been functioning perfectly for approx 9 months but all of a sudden it's leaking NOT from the tap connecter but just under where it actually connects to the casing, there is no apparent thread it just keeps spinning around when I try to tighten it. water is gushing out and goes into the casing behind the flip lid. Does anyone have an answer pls.