I'm worried about the fact that they sold the frog, too, since not all frogs are suitable to keep in the same tank with fishes; their poo is poisonous to fishes. Just can't remember which ones...
The habitat is not the best for the frog anyway:
"It is commonly suggested that these frogs be kept in a group of two or more to their social nature. A minimum of two gallons per frog (since they are each around two inches when streched out) is needed to keep these frogs, as they are very active and need the space to move. Despite being fully aquatic, the African dwarf frog still needs to be able to reach the surface to breathe. Very high or deep tanks over 20 inches in height are not recommended. These amphibians are not great swimmers, so water currents should be kept low. Very deep tanks may pose a challenge to their ability to breathe. In the wild, the Congo forest floods yearly to a depth of 24 or more inches. So anything less than that will be suitable. They also should be kept in an enclosure with a secure cover to prevent escape and plenty of hiding spaces as in the wild they tend to be prey to a variety of animals and causes skittish behaviour in open spaces. The optimum water temperature for aquatic frogs is 75–82 °F. The pH value in the tank should be maintained between 6.5 – 7.5.
These frogs cannot survive out of water for longer than 20 minutes in low humidity as they will dry out.
They are compatible with most bottom feeders and algae eaters. Respectful tropical fish can also be used as tank mates, although aggressive fish will often fight or injure the frogs. As African dwarves are slow eaters, it is not uncommon for tankmates to eat all the food while the frogs go hungry. If this becomes a problem, methods of delivering the food directly to the bottom of the tank (such as with a turkey baster) should be employed to ensure the frogs are adequately fed."
Wikipedia
