Stereo system and cigarette lighter not working in my santro gls ?

Hi, I bought new santro xing GLS model, and got it fitted with Sony Xplode and Cig-Lighter, it was working fine for about 2 days, and then all of a sudden it stopped workng, what i mean , there s power at all, in these 2 things, rest everything is fine, tell me what to do.