Before you make them any payment, read this:
https://legallyindia.com/convos/topic/253920-mca-registered-visa-consultants-doing-scam-and-breaking-consumer-laws-repeatedly
These people have threatened legal action against their critics for posting genuine grievances on consumer forums. They are morally bankrupt, horrible people and just want your money at all costs.
This is an industry wide problem as this industry is not regulated.