IndiaBulls — complaint against my home loan payment not releasing as per pro rata

Address:

Noida, Gautam Buddh Nagar, Uttar Pradesh, 201301

As per pro rata I would have to pay 12 installment of my home loan but suddenly infiabulls have change their mind and not release 11 installment to say that i should have to pay 11 installment and they will pay 12 installment... And why should I follow their changed decision if I already have written pro rata with detailed slab of payment
I already compaint to concern person but he response like [censored] & my builder adding late fee charges as day by day