Confusions about the job

I work as a project manager in a multinational firm, and have some confusions about this position as below
Firstly, i think a PM should be a leader of a team, and direct the internal execution of the spec, quantity, and schedule of the all the phases of the project from kick-off through production. However, in reality, there is no power in the PM's hand, so meaning that others function departments don't support our work very well. For example, provide the often reports are not submitted on time, individuals don't implement the work you assigned in time, or individuals are vague and unfocused on their work. In these cases, I have to face a lot of complains from clients, side since we are the bridges between the customer and the factory. Sometimes i feel tired but have no idea how to fix the problems (this sentence is unclear, so I am not sure what your meaning is). I think it there must be a problem of with our firm's management system. I advise that a PM should manger a part of the performance of the team members, maybe 50%, and the other another half should be managed by from their directors. This way, the PM can manage the project smoothly, but and have seem high-level do care of that,.
How about your situation or your firm's management system? Please give me some advises on how to do the job well. Moreover please help me to correct the composition kindly.

Confusions about the my job

I work as a project manager in a multinational firm, and have some confusions about this position as described/detailed below:
Firstly, I think a PM should be a leader of a team, and direct internally the execution of the spec?, quantity, schedule of the all the phases, from the project kicking off through to production. but However, actually there is no actual power in the PM's hand, someaning that others function departments don't support our work very well, for example: by not providing the report not on time or dont by not implementing the work you assigned to them in time. When even someone is vague and unfocused on the work, then I have to face a lot of complaints from clients, side since as we are the bridges between the customer and factory production, so sometimes I feel that I have tried but have no idea to them(but they don't understand? - I'm not too sure what you are trying to say :)).I think it must be the problem of our firm's management system, so I would advise that the PM should manage a part of the performance of the team members, maybe 50%, and another the other half fromshould be managed by their directors. This way, the PM can manage the project smoothly, but seem high-level do care of that,. and have high-level support to enable this.
How about your situation or your firm's management system? Please or give me some advice on how to do the job well, and moreover, please help me to correct the composition kindly.

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Good job :)