Mahanagar Telephone Nigam [MTNL] — MTNL 27353127 phone dead from past 4 months

Hi Concern,
My MTNL phone is dead from past 4 months and we made a complaints in MTNL office but no body listen.We are regularly paying the rent of the phone every month in fear phone become dead permanently.Called so many times to Shakti nagar exchange and no body listen.Please help to correct the phone or refund my submitted amount of 4 months rent.