For the yellow spots you can try using jewelry polishing cloth to polish see if you can lighten it. It’s less an issue since you can always replace them (likely Chanel will charge since it’s more than 1yr). Make it a point to wipe it after each use.
The leather peeling looks like it was accidentally brushed against some rough surface and deteriorated from there. Cos once an area starts peeling every subsequent rubbing (against any surface), even if gently, will further aggravate it. Unfortunately leather can’t be repaired, only can do a touch up. If Chanel doesn’t help you will have to look for shops that does.