Prox — fraud company

Website:

ffwork.in

I contacted PROX company from ClickIndia for genuine online work, but I realise now that they are a scam. They asked me to complete 900 forms in 9 days, which was backbreaking work and i completed it with so much effort, but they say that my work was not acceptable. If they really were genuine about the work, they would have given some more time and better instructions. I even had to undergo physiotherapy for my shoulder and neck pain. Wherever I had doubt, I checked with them and did it, but still they marked it as wrong. Now they are threatening me with legal notice and asking for payment.
I find many people have fallen into the similar scam. Please advise.