Punjab National Bank Housing Finance [Pnbhfl] — mortgage loan

We have a 5 yr fixed interest contract. However they have increased the interest rate where as the interest rates have actually substantially decreased. They have increased my fixed installment against terms of fixed rate contract.
R ref. No. Nhl/mls/1216/342065 sanction letter version no. 7.

Need quick redressal of the cheating done by the company.