Hi Elle,
Oh. So in a nutshell, I can either stay stuck with reporting that won’t take into account refunds / returns or I can pay Shopify an extra 2% (on top of my monthly subscription) to make sure refunds reflect properly. 
I hope you do realise why this doesn’t quite go down well.
I’m also now discovering the product exchange process is anything but straightforward and requires refunding and then asking a customer to place a fresh order.
Thanks for your help, though. Appreciate you taking out the time to help me here. But must say I am extremely disappointed with Shopify - basic features which you’d expect to be baked in require paid apps, and it’s anything but straightforward. Will manage I suppose, at least till we can pay a developer to move us to a better platform, one that includes basic features as part of the main subscription.
cheers