Will we get our money back?

Yes they should offer you a refund or a replacement if the set is under one year old. You have your statutory rights under the sale of goods act 1979. The product is not of satisfactory quality and not fit for its purpose. If you have any further problems accessing their returns department, call trading standards. It doesn't matter if you kept the packaging. My goodness, we would be knee deep in cardboard and paper if we kept all packaging. See CAB info on link below.