Consumer Redressal

I had bought a sony vaio laptop in May 2013. After 3 months of usage, it malfunctioned and i had approached Sony Authorised service centre for the same. According to them the screen of the laptop had to be replaced. Its been a month and after repetitive enquiries, my laptop is still not repaired. They say that the part that has to be replaced is not available. Please help me with the case as my laptop is under 1 year warranty.