Air India — Forced to pay extra amount for excess baggage

I was travelling from Hyderabad (India) to Kansas City (USA) through Air India/ Delta Airlines (origin to destination is on same ticket), I paid fee for my excess baggage in Hyderabad, but later when I reached Bombay (for connecting flight - supposed to be Delta but had to take Air India again because of their delay at Hyd airport) I was forced to pay $200 again for the excess baggage (for which I already paid Rs. 4570 at Hyd airport). I called number of times to Air India customers for help to resolve this issue, I was given 2-3 phone numbers but none of them couldn't able to help me (at least they did admit that it was their fault to collect extra amount). Attached are my receipts at Hyderabad and Bombay.