1. Collect all relevant evidence, including contracts and chat records.

2. Call the police immediately and complain to the local consumer protection agency about the intermediary.

3. Contact the bank or lending institution to explain the situation and stop repayment as soon as possible.

It is also a wise choice to seek legal aid. Lawyers can help recover losses and safeguard their own rights and interests.

5. Be extra cautious when dealing with intermediaries in the future, and you must choose formal and reliable institutions for loans and car purchases.