anyways i can get my alexa microwave to work?

     the microwave i used to have broke and wouldnt heat it so i got rid of it, went into amazon and thought i was just getting another microwave and then reallized it wasnt like the usual ones, i cant ever cook anything in it cause it goes into defrost, i think i only cooked something once for a minute, i chatted with amazon about it and they replaced it and the new one came today and its doing the same thing, cooked once for a minute and now it goes into defrost, i gave my other one to my neighbor and told her if she can figure it out she can have it, any ways to get this thing to work so i can use it? i asked amazon to send me a different kind but they can only replace it with the same type, do i need to trash this one too? any suggestions? they have a microwave downstairs but its on top of the stove and im 4ft5, any suggestions? i shouldve gotten a different one, thought of giving this one away and getting another kind