Hindustan Unilever — domex fresh n clean toilet cleaner

I bought this product to keep my toilet fresh and clean. I used this product on toilet seat and left it for some time. By the time i washed it, it had dried and after washing it left permanent blue stains on the back seat cover and on the main seat cover. Even after a month of washing these stains reuse to go. My new seat cover is permanently damaged. I am very very disappointed with this product. Please put warning on your product so that people do not suffer like me
Thank you
Jyoti ahlawat