Karbonn Mobile UNDER WARRANTY MOBILE NOT REPAIRED

Dear Sir/Madam,

I purchased a new karbonn mobile phone. Due to problem in charging and display in it during warranty period I submitted it to Service Centre on 06/06/2015 but one month has been passed, my phone has not been repaired, I made many call to customer care centre no. 18602004660 but not received any solution. whenever I called they say it will take 10 more days but as one month already passed they could not repaired it and I am facing problem due lack of phone. So I want to resolve the issue at the earliest. Detail of the phone and complaint is as follows:
Model No. : A 51 PLUS
IMEI NO. : 911380555354228
Submission Date : 06/06/2015
Service Centre : Vaishali, Ghaziabad, U.P.
Job Sheet No. : KJASPUP444615KR2804
Complaint No. : 173651

Hope to hear from you soon.

Thanks & Regards
Jitendra