Epcg non fulfilment penalty confusion

My Epcg is of 4 Lakhs from Jan -2012 to Dec 2019.

First block of 50 % export is not fulfilled by me till Dec -2017.

I am not getting block wise extension now. I have two queries-

1. I will do remaining export of block 2. What will be duty penalty and interest. Will it be on whole duty of 4lakhs +Interest. Or it will be proportionate to first block only is 2lakh plus interest.

2. If I fail to do the remaining export also. What will be the duty and interest.

3. Is there any limit on interesr.? From which date interest is calculated. It is simple interest or compounded annually.?