Replying to Not true slo-mo?

Hey NS - I have a few questions! To start off, I shoot on a panasonic lumix fz200. It says that I can shoot at 1080 60p, but I can't really slow down my footage without it being choppy. I even put the shutter speed at around 1/400 or so. Am I doing anything wrong, or do I need to do something different?

Under the video specs section on B&H it says:

Full HD 1080 60p video recording offers high quality video capture and High Speed Video enables the recording of fast-moving subjects at 120 fps (frames per second) and 240 fps! Active Mode and POWER O.I.S enable you to use the incredible zoom capability of the FZ200 in video modes too and all of this is available with noise resistant Dolby Stereo audio recording. Video recording can begin with just the touch of one dedicated button, a one-button switch from still photography to video.

Thanks NewSchoolers!!!!