Hisense broken screen

<p>I bought a Hisense Infinity F31 Gold cellphone on Thursday from Dion Wired Blue Route branch . The box was not sealed as a previous customer had apparently viewed the phone. But the salesman told me all was in order. When I got home and removed the screen cover I discovered that the screen was cracked. As I could only get to the store on Monday they told me they could not replace it as I waited too long to bring it in and there was nothing they could do for me. I told them it was within the 7 days as per their rules they still maintain they can't replace or repair at their costs. A new screen will cost me over R1000. What do I do?</p>