PayPal tax didnt consider refunds

I have a paypal business and I recieved my 1099K form and the gross amount on the form was more than I actually recieved. I do a considerable amount of refunds and paypal doesnt deduct that from the gross amount so im getting taxed for the transactions I fully refunded. Say I had 35,000$ in gross amount and I refunded 10,000$ of the 35,000$ making the net/actual amount 25,000$, How would i go about filing it?