Spice Jet Airlines — Service

To Sprice jet,
I have booked tickete from Durgapur to Mumbai SG 355, RHFSXN, seat no. 11A, I have 400 rs extra for window seat, but in that plane, window is not there so i requested for window seat, but crew not provide me window seat and told me you will get refund. I have filed complaint, but I received Rs. 312 vouchers but my window seat amount is Rs. 400, So I requested them refund my amount. I don't want voucher but Mr. Naveen Chhetry again again sending voucher email Rs. 312, It is very unprofessional if I paid extra amount and do not get that service then your responsibility to pay refund.