How to find the right person to speak to at a company?

I am following up on How do I pitch to a potential partner? I found the project manager who in the department of the company i wish to work with but however she forward me to 5 managers in smaller teams and i cannot help to feel but this is going the wrong direction (i dont understand why i was referred to them, i asked but got no reply)

One answer suggested i am not talking to the right person and i should find who has authority. I thought this would be the project manager but i don't think so anymore. Anyways the problem is

How do i find the right person to speak to? I haven't pitched yet but assuming the case she does not wish for me to speak to someone higher up or even the odd chance of she does not know herself, how do i find the person to speak to?

Side note: I got this contact by asking someone i know of who works in the company. He doesnt know who else i should contact if not that project manager.

If she, for some reason, does not want you to speak to someone with a higher authority, there must be a reason.

If you feel like there is not, it's best to speak to her again instead of wasting your time with those 5 other people.

Be carefull though. Do not assume these 5 people or the women are not who you think they are. Because it can get confusing and awkward if she, for example, ís the project manager.

It's important to be pursuasive, yet polite. When you said she did not reply, I was thinking: "Why didn't you ask her again?". It's best to get your information straight before heading into something.

To sum it up: The best way of finding out who to speak to, is by just going to the company, and explain to one of the employee's what you are here for, and ask him/her who you should talk to.

If the person you are supposed to talk to turns out not to be the women you spoke to earlier, it is best to go to that women first before doing anything. Obviously there was some form of miscommunication.

have your contact at the company set you up with a warm introduction. The best approach is to ask for 5-10 minutes of her time, when its convenient for her. Use the 5-10 minutes to find out if there is an interest, if there is not, move on and follow up in a reasonable and respectable time period (6 mos?).

Introduce yourself, thank her for introducing you to the smaller teams, let her know you value her opinion and would like some direction. In my experience its always better to ask advice from someone and use a subtle pitch. If you are selling, form a relationship or some sort of rapport first.

You find the right person to talk to at a company by extracting information from the contacts you do have there. Talk to your fried who first set you up there. Talk as many times as you can to the project leader. Be friendly and don't push your sales info. Your goal is to set up a relationship with this women. You use this relationship to gain as much information as you can. This will eventually (hopefully) lead you to another contact, who may or may not be the one you need.

This is all part of being a good salesperson. There is a reason why sales people tend to be chatty. All that talk gets you tidbits of information.