Time limitate good

I bought the mug so that I can also drink at home Slush. I immediately realized that although it is not as perfect as a normal slush (ie from the machine) but that does not Storte me on. I now have the cup, just six months. Initially worked as a law in ordunung I've put in in freezer and then poured and kneading a sugary drink. Allles no problem, but now the cup is with me already for 1 month in the freezer and it is not working. Actually was the yes after 3h hard but now everything is still quite fluid. Who can live with it dasss the slush we look zemanschtes water ice and that the cup after a short time breaks can to buy then do the its purpose but the dahmaligen 17 are too much money.