Hopefully you've got the right model listed here, as the MCS-360H is a Swedish Massage Cushion.
Did you remove the screw from the back of the unit before plugging it in...? The unit will not work properly until that screw is removed, and could be damaged if it is operated with the screw in place.
Here's the manual -
If removing that screw does not make the unit operate properly, contact Homedics Customer Service at 1-800-466-3342