Liverpool City Stays - City Centre Apartment

We booked this apartment in march for a trip away as it was a friends birthday, check in was at 12 and when we arrived we had been given no room number so we rang up and had no response, eventually I managed to get a text through and they replied saying our booking was cancelled because they had double booked us, because we had booked through *********** we rang them and they said they would get in contact with the apartment owner who never got back to them either, we payed for a two roomed apartment and ended up with no refund but having to pay extra to stay in a studio room with 4 of us. It is absolutely unacceptable the way they have treated us, I would never even consider booking with them again. The building is also still partially a building site with mess everywhere and rooms still being built