I know I am not in the UK but my take on dead fish is that casualties happen. I generally don't get two upset if I see a freshly dead fish in a tank at the pet store. Heck, i have come home to dead fish in my tank occasionally. It happens. I get mad when I see decaying dead fish, because that tells me they are not monitoring their tanks.
I only almost took mine back....btu we came to an agreement, so she stayed. Fish is crazy.
I can't imagine why A jewel would be a boomerang fish.They are one of the Boomerang fish... you can order them in because they sell well, but you can be guaranteed that at least 50% will come back to you! If not with all their babies too.
Jewel Cichlids
Red Tail Black Sharks/Ruby/Albinos
Synodontis
Plecs
Convicts