Hi I have had my unit for about 1 year and just

Hi I have had my unit for about 1 year and just today it turned into a ball of ice is it broken? It turns on and off but after it fills about a third of the way or so it turns to ice and sounds funny. This is the 2nd unit Ive purchased that has done this in about a year. I bought at home depot but do not have a receipt where do I take it or should I just throw it out. They are too expensive to keep replacing every year