Micromax A110
Service center has taken 2 weeks still, not returning my smartfone repaired

I had given my smartfone A110 (micromax) to service center (KAVYA ENTERPRISES, swargate) on 24 Dec. They promised to return my smartfone on 7th day. However, i didn't receive my phone on 7th day and continually taken follow after 4-4 days. They always says that parts are not available. Then, I contacted to service center and Customer Relations at 011-44770044. The Customer Relations representative talked me with rudely and said that, "if you want your mobile, come after 4 days otherwise do whatever you want. i don't care".

My job sheet number is AALMH294R1610

Please help me to get my phone repaired well.