return of item is disapproved by filcart which fall within 30 days retun policy and no proper resolution by flipcat customer care

flip-cart complain Nos
. 1. 140909-034172 on 9 sep
2.140915-056722 0n 15 sep
3.140917-028870 on 17 sep
return id. 7626801 0n 15 sep

i purchage asus zenfone 4 A450CG Rs. 6999 on flip -cart on 08/09/2014 i found some problem with this phone,i inform this problem to them via phone on 09/09/2014 they assure me resolve the problem upto 11 sep by 6:00 pmbut there is no reply from them when i contact them they extend time by 13 sep.but even no call untill(on 17sep). ther is 30 days return policy by them ,i also requeted to return on 15 sep but they send sms and email-your return request is disapproved by seller. plz solve my problem as early i am in very tension
thanking you