Question about Lexon Flip Premium

My flip alarm clock doesn't go off!!!!! I'm really annoyed and it's the second time... when I'm off work it always works fine, but when I have to go to work it doesn't work again. I set everything according to the instructions. I also tested it and the alarm clock rang without any problems. There is no way I could sleep through this alarm because it is so loud. I cannot recommend this product to anyone...