There is so much deceit and cheat in China, especially in the case of agents.

Others who deceive and cheat should also be mentioned in this context -they are rogue foreigners and rogue employers:

Rogue foreigners collude with rogue employers to avoid such employers having to pay the introduction fees owed to agents. A possible modus operandi in detail is for the FT to deny he is working for the employer the agent had introduced him to, on the instructions of the employer.
Another possible MO is rogue foreigners taking it upon themselves to deal direct with employers they were initially introduced to by their agents, so as to cheat their agents indirectly, and then negotiate better deals for themselves with their new employers, telling them how 'clever' they've been to prevent said employers having to pay agents' fees, and then asking for a share of said fees for themselves as a reward for their unethical behavior.
I can appreciate why agents are reluctant to supply contact details of jobseekers and potential employers to one another until both have agreed to sign a contract,and it has been countersigned, in which case an agent cannot be cheated out of his introduction fee by rogue employers aided and abetted by rogue foreigners.