Roca India / Parryware — Jet attached to the toilet seat is leaking so bad

I have a parryware cascade western type toilet seat installed in my washroom in my home. And the jet attached to it is leaking so bad. Earlier it was just a fee drops of water but now its worse and a whole stream of water is leaking though it. Local plumber looked at it and told that there is something wrong with the seat and the jet and the company should be contacted. Kindly look into the matter as earliest as possible as a lot of water is getting wasted due ro the leakage