Indigo Airlines - Unfair amount charged for extra baggage

Hi,
This is second instance with me in last * months, *st instance was Indigo customer care executive did not respond to my senior citizen parents nth-number of phone calls and finally they settled the incident with me by providing lum sum amount of Voucher worth **** rs. But I guess I allowed them to repeat the similar mistake within short span of time, recently when I tried to book extra baggage of my senior citizen parents under International connection flight policy,it did not allow me complete the process successfully, when I came to know about this situation I contacted the Indigo customer service over web-chat, but as usual I did not get the proper answer, then I connected with telephone call center from my International number and some one helped me to book the extra baggage for my parents flights, now my concern is simple why I was not able to do it whereas Indigo team can do it ?? do they manipulate with the information tech. system. as an Information Tech. professional I know this kind of thing only happen only some one from internal information tech. support team member is supporting the business.due to this whole scenario i had to pay **** rs.extra.I have provided Indigo team my web history, call history since **th May ****, nobody is responding appropriately. since last few days i was getting standard reply from them-"our concerned team is working on issue we will get back to you" and suddenly few days back I got the reply we did not find any thing on this issue, so I asked them about their findings.and again waiting for their reply.

Regards,
Jaymesh Shah
(+**) *********