Vish,
I would write to the CEO and marketng manager. (addresses in thread above) Go straight to the top.
I believe my contract started in about April 2007.
I don't buy the "system won't accept a tariff' line, that's an out and out lie.. If you get to speak to someone again I would tell them that you know people who have had tarrif reductions in the exact same circustances as you, so the line they are giving is not true. Tell them you know they are making decisions on a case by case basis and want to know the reason why they will not give you a reduction given the fact they have given it to others.
Again, try and be as polite yet firm as you can.
Good luck, let us know what happens.
Raj