Ohh...
Can you please tell me how can I launch a complaint and to whom?
There is no way to make a complaint with.
Is there any way I can get my money back or at least teach him or her a lesson kindly guide me. Thanks
No, your money is not recoverable. Once a Bitcoin transaction has confirmed, it is irreversible. If you send money to the receiver as part of a trade, you should let him know that the transaction has been confirmed and that it was paid to the address that he asked you to pay to. If he can't see the money, that is his problem; the blockchain shows that it was paid and the trade should continue.
This is sad, but completely true. Bitcoin is a safe-haven for criminals who suffer zero legal repercussions for such actions. People on this forum get away with scams... I have even been scammed here.
To stop this from happening in the future, never send money to a shady company (like the one you did). Always make sure you double-check the receiving address and send a large enough transaction fee so it doesn't get stuck.
If you do these things, your chance of getting scammed is a lot smaller.