Nothing works on my Apple Watch

Nothing works on my Apple Watch.. the buttons work sometimes but it has its moments where they don’t. The touch screen never works though. I’ve cleaned it. Forced to restart it. Unpaired it and repaired it. And updated it. If I do make an appointment in the Apple store, will they actually be able to fix this one? Or will I have to buy a new one? And how much will it coast to get it fixed. Because I just bought it...