Cugl - Excess bill amount of CUGL Bareilly

I have availed CUGL connection at Bareilly having CRN NO DB*****. I have made all my payments of Rs **** on **.**.**** and my bill was generated on ** sept ** with clsoing reading of *** units having Rs ** per unit rate.
Since sept **** i did not get my bill from CUGL and i asked for my bill sent my meter reading also but CUGL staff said you alresdy made advace payment and your reading was not upto that amount so we cannot generate bill for that period becasue your meter reading is very less and amount paid is extra. So we will adjust in coming bills.
But since sept ** company did not send a single bill nor generated it and now on ** sept **it send with close reading of ***.
Since sept ** to july ** i was at Bareilly and i did not get my bill now they charged all my bills with Rs ** per unit amount.Since july ** to till now i am in delhi coz of my transfer and house is locked.
During sept ** per unit rate was Rs ** now rate is Rs** so why should i pay with increased amount. That Rs ** was also increased from ** aug **.
But CUGL office Bareily became reluctance to pay the bill with New rate only. Why shuld i pay with new rate. This was not my fault.
Cugl not generated bill.