My meter recently developed fault and the DisCo placed me on estimation. I do not understand why the estimate is far more than what I used to pay when I had a meter.

When a metered customer is placed on an estimated bill, the average of the last three (3) months bill will be calculated to arrive at your present bill.

However, NERC has issued an Order that new meters must be installed upon the removal of faulty/obsolete meters, and the customer shall not be placed on estimated billing on account of the DisCo's failure to install a replacement meter after the removal of the faulty/obsolete meter