A complaint filed in the right place follows a moving company forever: it shows up in the federal database, appears on reports like the ones on this site, and can trigger fines and revoked licenses. Here is the order that works.
File at nccdb.fmcsa.dot.gov or call 1-888-368-7238. This is the complaint that lands in the federal record, categorized (hostage goods, deceptive practices, loss and damage) and visible to future customers for four years. Have your USDOT number, contract, and dates ready.
State AGs prosecute moving fraud, especially intrastate moves that FMCSA does not cover. Most accept online consumer complaints, and a pattern of complaints is what opens investigations.
For disputes up to a few thousand dollars, small claims is fast, cheap, and does not need a lawyer. Interstate movers must maintain a registered agent in every state they operate in; that is who you serve.
BBB, Google and Yelp reviews with dates, dollar amounts and photos warn the next family. Stick to facts you can prove.