-죠 (short for -지요) is the ending that invites agreement — 'of course', 'right?' — and putting 하다 after it quotes someone saying it, with no 라고 in between. Most of these lines quote a ready agreement: 그럼요 하죠 하죠, 했죠 했죠 했죠. Repeating it that way is how speakers show eagerness, roughly 'yes, absolutely, we did'.