If this is just slippage then it's usually just a matter of sanding it.
To do that on the S 200 you need to pop off the plastic (not as hard as it sounds) pull the cover, blow out the dust, undo a bolt or two (impact wrench makes this easy) blow out all the dust and sand the pads and bell.
While you're in there swap out your rollers to get rid of the flat spot, & check or even change your belt since you have it open.
There is another way to do this that usually works.
I do not recommend it since it has it's hazards & if you screw up you could injure yourself. I am adding this just to hit all the high points for as much safety as possible since someone else may put it up there half-a$$ed & skip the critical points since it's pretty easy to do and does the job most of the time.
If ya hurt yourself or someone else or your bike it's on you, not me. While doing this you could have the bike suddenly accelerate forward and it could be a little wild for a sec or two.
PUT on ALL SAFETY GEAR JUST LIKE YOU WOULD FOR A RIDE OR EVEN MORE SO.
Find a spot where you have lots of space in front of you to stop the bike if necessary. Don't do this where anybody will walk or otherwise move in front of you.
Really. Not normally an issue but if it is things get hairy while you have your hands full.
Mount the bike.
Start motor.
Hold brakes hard. hard hard hard. Have feet on ground as well or other means to keep bike stable. The center stand could be used but adds another lay of potential hazards.
Using throttle. run up the motor into revs that engage the clutch & spin it a bit.
Do this a couple, maybe three times..kinda depends, this is an art not a science.
You can let it sit a bit once after that to let it cool down or not. Didn't seem to make much difference.
Now try it and see if the clutch is no longer slipping.
If that got it, then next time you do pop it open it'll be kinda dusty, so clean it well.
If that doesn't you'll need to pop it open, & it may need more than deglazing, you can't tell until you're looking at it at that point.
Glazing's usually the cause of clutch slip, & clearing it is part of maintenance on this kind of drive train IMHO.
One final thought. I didn't do this since I sold my S & kept my SYM, but if I recall correctly, it looked like if you drilled one hole in the side cover you'd be able to get that last bolt to pull the drive train cover and slide the cover off without popping all the plastic. If you used a standard size drill you could easily get a pop in plastic or metal cover to fill the hole for normal use. I've seen this done on a few scoots for similar reasons, the HD for instance some do it on the lower side cover for the same reason.