Xperia-M mobile got problem within 5days after bought

Location/place: Hyderabad

Name of company/service: Sony India

Good evening sir,
My SONY Xperia-M mobile got problem within 5days after bought, I gave it in the Sony service center and they told it will be repared within 7days but its 20days over but not yet my mobile gave to me.
if call every time they are saying wait for some days, they even not gave any mobile to use,actually after bought if the device got a problem within a month they have to replace it , but not did that.
The ID NO:13090203273
Name:Raj Kumar
Mob:9908394080