Pexiv Company — they are asking for money

They have given me an assignment. But when i searched in google i found its reviews and understand it's fake so i replied them that i am not interested in this, after they have not contacted me. Now they sending spam mails and sms asking for money or else they will move legally. I know they are fake and spam as there are lots of complaints about them. So kindly looking into this matter and solve this. I don't want these fake people to contact me again.