The kick start is not supposed to be daily, it is supposed to be as a tool in case the battery dies, practice the technique in the video so that you are familiar how to kick start the bike correctly. If the Engine Case is broken due to kick starting the parts are not covered under warranty.

Kick starts don't work by "vigorously kicking them" there is a technique to it.

Here is a video on how to kick start a scooter. Once you open the kick start lever rest your foot on it the let go again so the kick start is at the top of the gear. Then rest your foot on the kick start again and do one quick motion down and release. You don't want to stomp it into the ground, or step on the kick start lever all the way down to the bottom, you will break the case.

Video on How to Kick Start your Scooter