The FCC Consumer Help Center Complaint Data API integrates customer complains. It is available in JSON, XML, and CSV formats with a token. Documentation can be found in the link provided by Socrata.com
Sixteen APIs have been added to the ProgrammableWeb directory in categories such as Government, Healthcare, WebRTC, and Transportation, among others. Featured today is an API from the FCC that provides data gathered from consumer complaints. Here's a rundown of the latest additions.