Kesari Tours — no response on the concerns raised

We have booked paris tour starting from 30-apr. The tour was with the direct flights from mumbai - paris by jet airways. We didnt received any communication from kesari upfront about any alternate arrangements being made or not.
After multiple calls we received a mail from borivali branch manager that we have to pay 22000 extra per person and the alternate arrangement is thru air india flight via delhi. The return flight was earlier scheduled from amsterdam which they have changed and now we need to travel back to paris for amsterdam and then take air india flight from paris to delhi and halt at delhi airport for 7.5 hrs!!! With this we will waste 2 days in just travelling and waiting on airport. We had not taken any leave on the arrival date as it was arriving early morning. Now instead of morning we will be reaching in the night.

There is no justification or explanation provided from where the amount of 22000 is arrived by kesari. When we asked about it they gave the standard below reply -
"there is no any alternate option for our tour.
Given flight option is finalised by management.

Sorry for inconvenience cause.

Also unable to give you breakup cost of flight details."

We cannot just pay any x amount stated by kesari, proper explanation should be given and this is a customer's fundamental right to know what he is paying for. Its nothing personal information of kesari which we are asking for.
Also when there are multiple other options of flights available from amsterdam with total duration of 12 hrs with just 1.5 hrs halt why we should wait at delhi airport for 7.5 hrs!!! This is totally unacceptable.

When we asked to the sales manager - sheetal, she also gave the standard answer as this is what is the option available. There is no justification of 22000 received yet. And now they have stopped replying.

Kesari must be having contingency plan in place then why kesari is forcing us to take an option which is not at all suitable and asking the money without giving any proper justification?

Is there any solution we can expect from them?