Letsbuy.com
Payment is done and they are still saying payment not received

I have ordered a samsung chat222 order number is LSB-463471 on 9th october my transaction was successful and my account was debited for the same. on Monday morning when i called lets buy customer care they are saying they have not received the money in there account now what to do i am not getting any thing now they are refusing to give the same my money is blocked between there hand i have given them bank PRN (Payment receipt Number) 4126367 a part from this i have given them confirmation mail also of bank for debit of amount were clearly name of lets buy.com is mentioned now what to do let me know. were should i make complain against them