Samsung — Phone is heating

Address:

New Delhi, Delhi, 110065

I buy the Samsung phone galaxy e7 On 30th Aug. I have used the phone only for 36 days and while charging or continues using it is start heating very much due to which phone's back started removing his paint. I have filed the complaint against this and the service centre is asking me to pay the money of 3400/- amount to repair the damage and they were saying it is not cover under their guarantee policy. Request you to help me on the above issue.