In my country if a customer wishes to complain about something from an establishment he first does so by submitting a formal complaint to the establishment, itself.
For example, let's say a customer has received poor service from an employee of Company A. If he so desires he can write a complaint on a sheet of paper, which does not require any sort of formal approval, seal or notarization, and present it to Company A, which then is obliged by law to receive it, enter it in their log of complaints (a formal log/book in which all complaints are stored with an internal identification number) and give a response within three business days. Note the Company is not required to fulfill the customer's desires, agree with him or take any action, other than acknowledge the complaint, itself.
I've happened upon this site which, as I understand it, says that a complaint similar to the one in the example above must be submitted to court to have any meaning and submitting one to the company has no value at all.
I am curious to the US equivalent of what I have described.