BSNL/[protected] — Speed of broadband connection

I am using broadband connnection from April 2009.There was satisfactory speed on that time.But from last one month speed is very slow.There is no responce from Bari local exchange reguarding this mater.The line which is coming from exchange to our computer is in very poor condition.There are so many open joints in this line.So connectivity of internet connection is not proper.Please do need ful for change of this line.So speed may be proper.