already filed and served on

14:00 Feb 18, 2017 

Thanks for your clarification. It did not convince me to change my mind, however. The decision is up to the asker.

11:43 Feb 18, 2017 

In legal terminology, a complaint is any formal legal document that sets out the facts and legal reasons (see: cause of action) that the filing party or parties (the plaintiff(s)) believes are sufficient to support a claim against the party

Above the "filing party" means طرف تنظیم کننده شکایت and not طرف تشکیل پرونده دهنده. File can have various meanings. For example file an action means طرح/اقامه دعوی کردن. Please refer to Mehrdad Moslehi's specialized Legal dictionary.

In the definitions provided by you on serve the word "send" is used. Please notice that when we talk about a complaint and this happens in a court, complaints are submitted to the court, thus تسلیم دادگاه کردن.
Best,
Younes.