Hello and welcome to FF . Sorry about the injured frog . A skin wound could be treated with Melafix; but a broken jaw could fix itself or maybe not.

Bloating can be caused by renal failure, which after that fall, is within the realm of possibilities. Or the frog may have a bad internal bacterial infection, which could eventually become contagious to the other frogs. If an infection, a stronger antibiotic like Mardel's Maracyn Plus (works against Gram + & - bacteria) is prescribed.

Myself think the frog received internal damage during fall and recommend it be returned to the store. The employee should have never sold that frog to your Mom after they dropped it .