We have had damaged goods in our deliveries from both Tesco and Asda.Both were easy to resolve. Asda has an option in the Your Orders section of their website and Tesco was a free phone number,phone answered quickly,very apologetic.In both cases refunds were in our account within a couple of days.
As TwiceAsNice - COMPLAIN! You'll be offered a replacement, so decide if you want that or insist on a full refund, prior to making the call, then just do it Oh! and will you come back and tell us how you got on? I think we could compile our own Database of shops which have given good/bad value in this time. All the best.