Damaged goods but refused to replace / refund

I ordered 13 Deanta oak internal doors from Builder Depot Limited online. Deanta's own care instructions say that the doors must be stored flat on an even floor for 7 days at a steady temperature to acclimatise them before fitting. The doors were delivered to us upright on a pallet lashed together around the middle. We immediately laid them flat and followed Deanta's guidance. Our joiner started to fit the doors about 2 weeks after delivery at which point he discovered that the veneer on one of the doors was cracking quite badly. We discovered another door with the same problem. This was really difficult to identify under the plastic shrink wrapping. On complaining to Builder Depot, they responded to say that Deanta say it's not a maunfacturng fault and it must be the way we stored the doors. Builder Depot refused to either exchange or refund. As far as I'm concerned, it's the transportation arrangements which are at fault and we have a right to a refund for faulty goods. We are pursuing this through our credit card company but I feel badly let down by Builder Depot and could never recommend anyone to use them. There are also problems around items not being in stock, missed delivery dates, non notification of delivery and a host of other issues. Avoid like the plague, the cheaper prices are really not worth it.