Had a talk with the Sub Divisional Engineer and was shocked to see his knowledge on the topic. According to his system, the downstream rate shows 2047KB and not 708KB, and moreover he said that 2047KB is standard and "downstream rate has nothing to do with speed". He also said that tampering with these settings can cause to further problems in connectivity. In one word, he is unwilling to do anything. I wonder how these illiterates and lazy guys manage to get job at BSNL, with no knowledge how the system works. I highly doubt if his qualifications are apt for this job or not.
Anyways, I have given them last warning that if the problem is not rectified within a week or so, I would be disconnecting. In the meanwhile, I am having talks with my society secretary, if we somehow drill a new port for wires to come to my house, but so far no luck there.