MakeMyTrip India — international activity

I used makemytrip app to book an international activity on 2nd oct 2019. The booking voucher was generated on the app itself (Screenshot attached with booking id and qr codes). The activity was scheduled for 12 oct 2019 in venice, italy. I reached the vendor location before time and showed them the mmt voucher. But they refused it saying that they are looking for a different voucher than one mmt generated on the app.
So then i called up mmt to resolve the issue and they said that a different voucher was sent on 10th oct on my email.in the meanwhile, vendor left with his ship and i was stranded.

So my issue is that first of all, makemytrip didn't call me to inform that a different voucher would be needed to redeem the activity. Also the voucher was sent very late, just 2 days before activity. How can they expect me to read my mails on vacation. And lastly the vendor they were working with had no information on the passengers names who would be travelling with them. That is very unprofessional.

I request a full refund of rs 2678 from make my trip.