I want to return the ring
Is there a reason you want to return the ring?
Yes, I don't like it but my fiance gave it to me.
I think you shouldn't return the ring because it would probably hurt your fiance's feelings. You should try to appreciate the thought behind the ring, even if you don't like the ring itself.
I don't care about her feelings.
That's a bit rude not to care about her feelings. Don't you think you should try and be grateful that she got it for you in the first place? It's quite a generous gift after all.