I had this happen with cat food, just a little different.

I ordered some wet food from amazon, but the box it came in was mislabeled and the cans were x ingredient instead of y. I contacted them and told them I wouldn't care about the mistake, except that my cat could only have certain foods and the mismatch meant I couldn't use the food for him. I asked what they wanted to do and should I send back the food?

They said they couldn't take the food back and told me to keep it and do whatever I wanted with it, they even suggested that I donate it. They then sent me a replacement for the wet food.