First off did the consultancy firm get your sister signed in on any agreement? You can send them a legal notice to repay you within 7 days failing which you can initiate legal proceedings against them.
For any further queries, feel free to contact me on 7601090381 or email@example.com
Please see this answer carefully
As per your submission it reveals that this is Matter of fraud
If you have address of that person who have cheated with you then through your lawyer you can send legal notice
Despite of notice if no amount paid then you can file suit for recovery of amount
This is Matter where civil as well as criminal litigation can be filed
For details discussion you can call me for advise through lawyered
Advocate IRFAN SHAIKH Latur Maharashtra
Mobile no 9359867870
Just send a legal notice to that consultant first. For any further assistance, feel free to contact me on my e-mail "firstname.lastname@example.org".
Shubham Pabbi & Associates