That's exactly why you should never ever trust dictionaries, unless you already know both languages.
- rendre = to give back when it's transitive (i.e. it has an object) (Je rends les livres = I give the books back). It can also have two objects, one direct and the other indirect (Je rends les livres à mon frère = I give the books back to my brother)
- rendre = to make when it's about a transformation. It has an object and attributive adjective. It means that you change the object into the adjective (Je rends mes parents heureux = I make my parents happy).
- rendre visite (à quelqu'un) = to visit (someone). It never means to visit by itself.
- rendre compte (de quelque chose) = to report (something). It never means to report by itself.
On the other hand renvoyer = to send back. In the context of this sentence, it makes sense, but it's not literal enough for DL.
Dictionaries can help you make sense of words once you have context but, I agree they are useless if you have no starting point. At least with WordRef you can go both ways but you need a good knowledge of English as well → gave back = returned:
I don't know what dictionary you have but you might want to replace it as rendre means "give back, return":
Thanks for you reply, and the subsequent responses. As you say, a dictionary can be imperfect.