Chains stores and pet "superstores" like Pets at Home etc don't know what they are selling, because they hire just anyone to work there and sell their stuff.
Fish are a specialist subject and each species is a specialist subject within it. Places that know what they are doing are spread quite thin. It's not like a cat where you just need to slap some food in a bowl and if it's gets ill you visit a vet.
The range of issues a cat (and dogs) can get is far greater and the medical science is far more complex so that throw away comment is just nonsense.
Treatment of fish diseases is more tricky because the over the counter 'medicine' you can buy in the UK (and probably Europe) for the most part isn't very good. All of the 'good stuff' is restricted and has to be prescribed by a vet because it contains proper antibiotics etc. This is not necessarily a bad thing, antibiotic resistance is very much real growing problem.
You absolutely can take your fish to the vet, well the vet comes to you. No one does it because they are not going to spend £80+ for a consultation on a £1 neon tetra. If you have Koi or a tank full of stingrays that costs £X,000 then you'll get a vet out pronto.
Yea they have those, but stuff in the tanks sometimes too.
P@H sell exclusively Tropica aquarium plants, no random nonsense there. The stuff in the tanks is also tropica, the quality just depends on how long they have had them.
they sell pond plants aswell so think it got placed in the aquarium plant tanks by mistake.
Pond plants will probably grow, as long as they aren't marginal ones.
It's not a pond plant, its very much terrestrial. Growing it out the top of the tank might work, it might not like it's roots so wet and a lack of soil. I would have taken them back or at least called. If they don't know they don't know.
I've been to WoW and its a well set up store, the only thing I wasn't impressed with was the plant selection. I didn't see anything from the likes of Tropica or Aquaflora etc. it was mostly just a small selection of cheap, bunched plants. Having read where you got them and my own visit there I'm leaning towards they don't really know what they were buying from the supplier and the supplier isn't very good. They had great range of healthy looking fish, tanks and equipment at reasonable prices, just not so much on the plant side. In the future just mail order them in from a specialist retailer like Aquarium Gardens, you'll instantly see the difference.