Ac Tech Solution — torturing me for paying 4999

Like all said i got call from them and submitted my id proof for form filling work and they asked me to signed an agreement which is not even seems valid. They gave me to fill 500 form in 5 days i accepted that but while doing so in the 2nd time while i logged in it didn't after that they are calling and asking for charges and sending me notice to pay money. I don't understand what to do.