The one who punished Echo was the goddess Hera, becuase Echo tricked her.
The god Zeus loved consorting with beautiful nymphs and often visited them on Earth. Echo was one of these mountain nymphs. However, his wife Hera, grew suspicious and tried to catch him in the act.
One time, when Hera arrived, Echo kept her occupied by talking continuously in order to make time for Zeus to escape. When Hera realized she had been fooled, she punished Echo by depriving her of speech, only leaving her the ability of repeating the last words of other people.