Flipkart — Money not refunded to my bank account but flipkart says seller has refunded the money

Address:	Bangalore
Website:	Flipkart

Hello Sir, its been 3 months I ordered a double bed mattress and returned it because they delivered it in bad condition. But after that it has been 3 months now they are saying they have refunded the money to my bank account. But i cannot find any entry for that, they asked me to share bank statement which i have done multiple times but everytime they close the request and say money has been refunded. Now they are asking for a charge back form from the bank. Bank is not entertaining me beyond this and when i asked them to share the refence number from seller they dnt give me that also.
I am so upset with flipkart now.