Bharat Sanchar Nigam [BSNL] — BSNL waiver of rent

Address:

House no.03 Kamil Lane Budshahnagar, Opposite Iqra Bus Stand

My area code is 0194 and landline number is 2434919, two months ago I submitted an application at BSNL exchange to change my BSNL broadband plan at Rs.899 to a simple landline plan at Rs.129. A month later I received a new bill will full amount at Rs.1049(gst included). After inquiring at the exchange they told me that they had processed the application but it was stuck due to system error and I wasn't informed bout it. After finally changing my plan they told me that I have to pay for the two month bill that I have received. I disconnected my broadband two months ago and haven't been using it at all. Currently my bill is Rs.1948 for two months, where I have not used any BSNL services at all. I find this very unfair, at the exchange they told me I have to pay it even though they admitted it was the systems fault. Any help would be appreciated.