Micromax — Mobile Under Warranty_repaired many times_Still Not working_Please replace it

Dear Concern, I have purchased my Mobile Handset Model A-120, IMEI No, [protected] from M/s Harjeet Brothers, Dharampura Bazar, Patiala against Invoice No. 3720 Dated 13.10.2014 From Last 2-3 months, it is not working properly and it gets switch off automatically, For which I have contact your Service Center at " City Center, 22 No. Phatak, Patiala" First Time, they told, it is a software problem and update the software, Problem of auto switch off not resolved properly, again we approach to Service center, Second time, they told it is a hardware problem and again repair it. Still same problem exists and Now they are asking to change the BATTERY, As per me, Battery is properly working and its Back-up is also OK, We can change the Battery but provide me the written confirmation that replacing Battery will solve the issue of auto switch off of handset and if even after replacing batter it is not resolved, you will replace the Hand set with New One. Considering above, I request you to change my Handset with New one OR give me confirmation that replacing Battery will solve the issue. Thanks Rajat Kumar [protected]