"Sorry we're unable to offer you a return as your item(s) were on sale" - what does this mean?
Your customers reached out to you stating that they received this message. And you haven't excluded any items nor do you have any items on sale? 🤷🏻♂️
Heading over from your Dashboard -> Translations -> Customize -> Select language. Once you're there, just search for the text you want to change, modify and hit that Save button. That's it. Your work here is done.