Claim rejected due property been vacant / unoccup

I referred my sister to outsurance in Dec 2014. She bought a property about 4 years back.<br> In the pass year renovations took place. As of Dec 2014 the major stuff was done in the property where cover was need. extended theft cover include. All plumbing and electricity was completed in Dec / Jan 2015. Proof of electricity is available. She indicate that no one is staying there. Cover was still given. The property was never vacant before and after the insurance was taken out. on the 26 Jan 2015 a burglary took place. they came through the tile roof. the alarm went off at 06:56, by 07:15 police was on the scene, but the theft was gone. a case was open on the scene by 07:30. Damages was due to the sink mixer tape been *******, and flooded the property. on the 25 Jan 2015 we were working at the property. outsurance is rejecting the claim saying it was vacant, meaning of vacant was that there is no curtains on or furniture in the property. Renovations is taking place... We requested the recording almost two weeks back till to date no feedback or recording. Spoken to the senior supervisor. no feedback. I made a mass mistake to referred her to outsurance hence the reason for my post.