Sorry to hear that Clarke, tho to be honest any cloth material jacket will leak, it's just the nature of the things, leather is about the only thing that keeps the water out. Even leather jackets leak in very heavy rain through the zips and air holes, if you ride in the rain your gunna get wet. I bought a cheap over suit thing some years ago, big zip from ankle to arm pit and it made you look like a Michelin man but it was the only thing I have ever found in 40 plus years of riding that even came close to keeping me dry. Just as an aside that is an awful lot of money for a suit that leaks and if it was me I would be looking at a replacement rather than a fix, just sayin.
I have been known on long trips to put a large black dust bin bag with holes for my head and arms under my jacket, it keeps your core dry and warm but you look a tit when you get off your bike and tear your kit off!!!