Incorrect Referral fee

Hi beautiful peeps.
Im selling an Asin under Baby category. Previously referral fee of 8% was charged to it. Suddenly Amazon changed it to 15% . It’s been more than 6 months now that my referral fee is 15% whereas my competetitors is 8% only. Our categories and GL codes are same too but my Category is Baby but Referral fee category is changed To Home n Kitchen…and they have refused to change it.

Any help here will be much appreciated. Thanks