but the agent or firm should be TRUSTED One
I just found out that there is an agent who can recover Bitcoins that have been sent to scammers, I tried to search on this forum, I couldn't find the agent you were looking for, what I found was as below.
After struggling for weeks to find any hope of recovering my bitcoin, I was pointed in the direction of a person called Dave at
http://www.walletrecoveryservices.com by a member on this forum. Dave was a fantastic support throughout. Not only did he successfully recover my password an enable me to access my bitcoin again but he gave proactive advice and support to me on how to transfer my coin and setup a secure new wallet once I had gained control of the lost wallet. I couldn't recommend Dave enough to anyone struggling to recover their wallets. if you are dispair ad need someone trustworthy to help get in touch with him
I don't know which Dave that person said, whether he succeeded or not, it's clear from his words that he seems very happy because his Bitcoins can be recovered.
If i may ask what exchange do you use to send Bitcoins, local exchange or Trust Wallet or similar, looks like you should ask for help from the exchange or Trust Wallet to trace to whose address you are sending.