Sony India — Product repair/xperia z2

Address:

Burdwan, West Bengal, 713301

Dear Sir, on 4th january 2015, i, Abhishek Burnwal submitted my Xperia Z2 in Asansol Service centre as mobile screen was not working properly. they assure me that with 7 days same will be repaired. but till date no positive response received. whenever i called they ask for another 7 days. My job order is W[protected]. Please help me so i can get my phone at earliest.