Samsung S4 falling apart.!

On the 25th of February 2015 i took My phone in to be fixed on the ADH warranty, they told me to wait for it to be fixed so i waited 1hour for the technician to arrive. Once he got in they told me another hour to fix it after that hour i went back in. Just to find out that my phone was in pieces And they had no stock of the screen. Then they told me to leave my phone for a day. I told them to put it back together and call me when they get stock of screens! They put my phone back together and said they would call me the next day! Today is the 10th of March still no screens and i have to keep calling them! They never put my phone back together properly and it is falling apart! I am not happy and want this resolved immediately!