VIC A referred B to C for C's service. B doesn't pay. A's responsibility?

[NNg]

Hi, I referred a client to a business plan preparation company. This client now is not paying this company. He believe the company didn't deliever the business plan as his requirements and amendments requiremements. This client is a friend of one of my former colleagues. My colleague asked me to refer to him someone for the business plan. After I referred this client. This company and the client had telephone calls and face to face meeting(s), which I don't know, before the job was done. The company, however, sent the quote to me. I wasn't aware that was not very appropriate, so I asked my colleague to ask this client . My ex-colleague messaged me via WeChat that his friend, the client, said okay to proceed. I have records of the communication between my ex-colleague and me. I then emailed this company telling them the information. The company then worked with their client. My colleague told me later that a draft was provided but the client was not satisfied. The company emailed me several months after telling me that they need to bill this client. I don't know what happened later. Another several months later, the company told me that the client didn't pay. They asked me to help. I advised that I am not involved. Last week the CMO of the company emailed me telling me that this client hasn't paid and he gave my ex-colleague's name but no contact. The company is asking me to give contact. In the email he copied the chain with the email where I said the client is okay to proceed. I didn't give my ex-colleague's contact given it is private and I don't have any consent. I wonder if there will be any trouble for me.