Aquatic frog HELP!! 10 points?

Okay so i bought an aquatic frog for my fish tank, The Petsmart worker told me that the frogs wont mind goldfish. And they didn't. But Everytime i feed them Pellets (frog bites) they seem not to eat them, and even worse, the goldfish bite them and spit them out till they get smaller and swallow it! Should i return them, will they survive, or do i give them a little while? will they survive, do i give them a little longer? What do i do?!