Dameged goods

In April i made a lay bye at Russell's of a bedroom suit but i took it out on the 7th of June they told me i will recieve it on the 9th of June cos their storage is far,on the 9th of june i recieved my bedroom suit but at the bottom of the mirror there was a scratch but the delivery guy said he's gonna fix it he went out n took he's tool box n take out a ****y pen then made the scratch invisible he then asked me is it fine or must he take the mirror back i said no it was fine cos i no longer see the scratch a day after on the 11th of june i woke up on a big crack on the mirror i took a photo n went to the shop to show them but they gave n attitude telling me that i signed for the suit that it was fine so now there is nothing they can do about it the only thing they can do is to make the quotation for me to fix the mirror n i must pay for it,i tried to call their head office they told me the same even on face book what can i do in such situation where the incident happened not even after a week only 1day n when i think now why the delivery guy asked me if he must take it back he knew something happened to that mirror