Hi @LouisaP, welcome the community.
Under the Australian Consumer Law, products supplied/delivered must be as advertised. This means if a product is advertised as being new, it must be in new condition when delivered.
It appears from information you have presented, King Living and its delivery services didn’t deliver a new lounge as advertised. As such, you have a right to seek resolution under the ACL.
I would be formally writing to King Furniture with a history of your experience with them, outline it isn’t your fault or responsibility that the lounge was delivered to the wrong address and was used by others for 6 days resulting in the lounge being delivered in a condition different to that which they represented on purchase, that being the lounge is new. This is in breach of the ACL (new means unused). As a result, you seek resolution under the ACL. An acceptable solution to you is that they take the ‘used’ lounge which was delivered away and replace it with a new lounge to which you paid for. Also say that if they don’t offer an acceptable resolution under the ACL, you will be taking it further with your local office of fair trading.