Thomas Cook India — wrong visa application done by the company

We had booked an uk europe tour with the company from 15th april to 29 april.. We have a close family staying in uk and thier was an function which we had to attend plus had to travel with our family to scotland and wales, which is why we wanted a small deviation in the tour that is instead of going on 15th with the entire group, we wanted to go on the 11th which was communicated to them on the day 1 before we booked the package also. On 25th january it was confirmed that the flight tickets to london has been booked for 11 april for which we had paid the company 25000 extra amount. Then there was an communication from thier end regarding the visa process, and it was clearly told to the visa spoc about the deviation. There was an covering letter also given to the company which stated the date of travel as 11 april 2018, still the company filed our visa date as 14th april 2018. We had the visa appointment on 9th february.. And the company handed over the documents and we went for the visa. We received the visa on 22 february. As we had complete trust in the company we did not notice the visa dates. It came to our notice only on 31st march, and when we informed the company, they blamed it on us that we did not see the dates. And now they are asking us to pay for the new visa cost or bear the deviation money cost.