Hi Jackie
Pets at home should take them back but might not give you a refund.
Fluval edges are great tanks when stocked properly but it just takes a bit of knowhow with how to choose the fish but we can help you with that
To be honest the best thing you can do if you take the fish back is do whats called a fishless cycle.
The lotions and potions you get with new aquariums are pretty useless Im sorry to say, the bacteria they claim to hold need a constant source of ammonia and oxygen and in a sealed bottle or tub this is impossible so the bacteria just dies off very quickly and the product is redered useless in the shops.
This is an article on the fish less cycle which is a good guide on how and why to do it this way
http

/www.fishforums.net/index.php?showtopic=113861
And this is all about the nitrogen cycle which is well worth a read as it explains all about what goes on in your aquarium especially in the early stages and how it effects your fish.
http

/www.fishforums.net/index.php?showtopic=271928&hl=
This is a link to the new members section where you will get a lot more advice on how to start up a new tank

http

/www.fishforums.net/index.php?/forum/26-your-new-freshwater-tank/
Also these are some really good online shops to buy fish from but postage is quite expensive
http

/www.tropicalfishfinder.co.uk/stores_products.asp?store=54
http

/www.tropicalfishfinder.co.uk/stores_products.asp?store=6
Where abouts are you from maybe one of us can direct you to a good shop near by?
Hope thats helped
Wills