You can track and report on refunds directly in Google Ads and Meta Ads on campaign, ad set and ad level. You can achieve this by setting up custom columns.

Google Ads:

Go to Campaigns → Columns

Click Custom column

Add a Name for your column, then click 

...and scroll down to select Conversions → All conversion value

Use the search bar on the right to find ReatkionReturnedRevenue and select it

Click the plus sign (+) and then click Column again and select All conversion value

Select ReaktionReturnedRevenue (Conversion Booster) and click Save

Make sure your custom column is selected and click Apply 

Exactly the same way you can add other metrics to your report by creating specific formulas:

Number of refunds:

ROAS after refunds:

Refund rate:

Meta

Go to Campaigns in the left side menu

On the Campaigns page click on Columns

Select on Customise columns

Use the search bar to find ReaktionReturnedRevenue (conversion)

You can add it as a Total to display the number of refunds and also as Value to display the combined value of refunds.

Click Apply to add the metrics as custom columns.