No delivery of goods paid for

I ordered an paid for 5 items on 1 November. For the particular books they said it will take 3-5 days. On 15 November they delivered only 3 of the items ordered. And when I said when will I het the two books outstanding, I was told I signed for it. I think the response lady was lazy and did not read because yes I signed for 3 items not all 5 and because the app does still show outstanding. The app also shows delivery by 16 Nov, however its 18 Nov and no books!!!