Hi Laura,
That doesn't sound good! Did you buy them locally? Perhaps you can return them and get others? If you bought them mail order, email the place where you ordered them from and explain the situation .. if they are a good site they should offer to send you more at their expense.
If you can't replace them, then cut or pick off the squishy bits and make sure it doesn't smell rotten.
What exactly did you order? There are tons and tons of different Colocasias.
