If the 1099-K is only reporting refunds for items you returned, then don't report it on your tax return.
The IRS doesn't "match" 1099-Ks to your tax return - at least not yet. Unlike 1099-MISCs and 1099-NECs, they aren't expecting to see a separate "1099-K" entry in your tax return. In fact, there isn't a dedicated place in TurboTax to enter a Form 1099-K (see screenshot, below)
If the amounts reported on a 1099-K are unrelated to business activities (e.g. credit card receipts, online sales for profit, rental income such as AirBnB), you do not need to report them. Keep the 1099-K with your other 2020 tax documents, along with any documentation that it was only issued to report refunds for returned purchases.