Lenovo (INDIA) Private Limited - Complaint not Resolved

We have Filed a complaint regarding Lenovo all in one pc purchased in **** , since purchase it crashes a few times every few months. In February **** i have filed complaint no.********** , where online diagnostic run by Lenovo Support , found defective harddisk . they have sent harddisk which was not replaced by local service engineer allocated by Lenovo. After that another complaint no.********** was filed in march which was not resolved but the entered fake data that it is resolved. In July ** , **** i have raised an escalation issue with them regarding my harddisk issue as it was having several crashes in every **-** days , wifi card gets corrupted and sound system not working ....i got no response till **th August ****. My system was working very slow and on **th Sep **** , it stopped working partially with no wifi icon and no sound i complained again Complaint No.********** , in between on **rd Sep ...i can only see a blank screen with mouse pointer , nothing at all. Lenovo again told my harddisk is issued and will be replaced by service engineer , but again service engineer did not replaced that. since than i am trying to contact them but they are only giving assurances but no real solution. My business is suffering severely , incurring huge losses as its all online . system under warranty till Sep****. attached all mail transcripts for reference.