Translation:Sorry, we can't refund it.
"Sorry, we don't give/issue refunds." Both should be acceptable.
GuyInParad is correct. Regardless of who is running the shop, be it a cashier, manager or owner, to say "We don't give refunds" is correct. Store staff in English will often say "We" when describing store policy.
Maybe it is the store clerk who have no control over their policy?
They might say "Sorry, we can't give refunds" sounds more correct
I can't speak to the Chinese meaning. The English translation is fine, "we don't offer refunds" and "we can't refund it" are not completely interchangeable. A store may offer refund policies, but refuse to refund if you misuesed the product, broke it and then tried to get your money back.
The verb "refund" can be used both transitively and intransitively. Therefore, the trailing "it" should not be required.
My own sense is that it's not commonly used intransitively.
Even so, "we can't refund it" is still a little weird, because the "it" has to refer to the purchase price, not the item being returned, and we would have to imagine a specific preceding sentence like "can you refund my money", whereas it's more likely that someone would say "I'd like to return this" or "I'd like a refund".
"We can't give you a refund" would be better, I think.
I'm not sure. Offering refunds is different to giving refunds. In fact I'd word it "We don't offer refunds" now that I think about it.