Jet Airways - Exorbitant deduction of refund

I hv booked * pax domestic airline ticket from Mumbai to calicut (CLT) on **-**-**** through 'yatra.com for travelling on **-**-**** by paying Rs. *****- (Booking Ref: *************.Jet airways flight No. *w****. When I noticed there is some changes in the name and initials of the passengers in the ticket v/s their aadhar card, I have requested 'yatra.com' on **th April, **** to get the tickets changed as per passengers aadhar card. However, they informed me airlines would not accept any kind of name change and advised me to cancel the ticket and rebook. Accordingly I have cancelled the ticket and rebooked on the same flight No. *w**** for the same date, time and No. of passengers and same sector without any change other than minor correction on the names and initials. However, to my surprise and shock airlines have deducted a whopping Rs. **,***- for cancellation. Also when I re booked the ticket its fare gone up to Rs.**,***- as against my earlier booking amount of Rs. *****/- losing another *,***/- Over all just for a silly mistake, I happen to lose Rs. ***** + Rs. ****- = **,***/-.
Request to refund the excess amount deducted .

Subsequently I received * e-mails from 'yatra.com askign me to furnish certain details for further refund and I have complied.
However, when they asked in the second mail asking me to furnish my credit card no, expiry date etc I did not provide it on dobt.
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