Makemytrip - Misinformation Lack of Information lead to Ticket Cancellation

Booked flight tickets from India to Singapore and return. Due to delay in visa asked CC to help with rescheduling to next day. CC connected to Singapore Airlines support but they said it's not possible to reschedule. I asked if I can cancel and get some refund but SA support asked for another *k just to cancel the ticket without any refund. During the whole conversation I mentioned to reschedule/ cancel only the onward ticket as I will be traveling once I receive my visa.

I didn't cancel the onward ticket because they were asking for *k so I booked another ticket when I received my visa next day. When I was at airport and tried to download the return ticket, I found out there is no ticket.

I called MMT CC and they said your PNR has changed and they will be sharing the new PNR on email. When I checked my email next morning in Singapore, I couldn't find any email from MMT CC. In the evening that day I called MMT support from Singapore asking about my ticket and they said your ticket has been cancelled.

So in short because I didn't travel with onward ticket, they cancelled my return ticket as well. Without any communication or warning even when I was on call with them for an hour saying again and again that I just wanted to reschedule or cancel the onward ticket and wanted to keep my return ticket.