It sounds like you had too small a ball for the coupler. Maybe a 2" ball but a 2 5/16 coupler? Check the writing on the coupler to determine what size ball you need.
Or else your trailer has a really-cheap coupler.
Was this a weight-distributing hitch or a weight-carrying ball mount?
Grumpy ole man with over 50 years towing experience. Now my heaviest trailer is a 7,000-pound enclosed cargo trailer, RV is a 5,600 pound Skyline Nomad Joey 196S, and my tow vehicle is a 2012 F-150 EcoBoost SuperCrew.