Bought R2,8k laptop at crusaders buh was not happy with the battery life

I bought a laptop at cash crusaders two weeks back in Bethlehem..and im a student at Qwaqwa. I came to Bethlehem from qwaqwa to purchase a laptop from cash crusaders. I bought it at R2,800. I went back to qwaqwa and I used the laptop the following day becuase I had to let it charge. The next day I opened the laptop and within 1hour 45min the 100% battery was depleted..I contacted the cash crusaders in Bethlehem and I demanded refund becuase the product isn't meeting my expectation. For a laptop that costs R2,8k I should be facing problems with it on the first day of usage..The employees said to me I cant return the rllaptop because of the 7days policy of return has expired and they cant fix the laptop either. I need help with getting my Refund i am not happy with their services.