No, Pope Francis didn't say that hell doesn't exist. That he did was the claim of Eugenio Scalfari, a journalist friend of the pope who doesn't share the pope's religious faith but who also doesn't have a recording or notes to verify his report, according to the Times.
People forget, perhaps understandably for a rock star, how traditional the pope is in his thinking. He often makes reference to the devil and the spiritual realm.
Here he is in 2015:
This is hell. It is telling God, ‘You take care of yourself because I’ll take care of myself.’ They don’t send you to hell, you go there because you choose to be there. Hell is wanting to be distant from God because I do not want God’s love. This is hell.
Every reporter in Rome knows that you cannot take Scalfari’s reports seriously, but his stories are just too sensational to be ignored.