Easemytrip - Misleading information

I booked a Thai Lion Air flight through EMT. I had to cancel the trip due to medical reasons. EMT adviced not to cancel but convert to open ticket and only airline rescheduling fee + fare difference would be charged.
Recently, I was planning the trip again and reached out to EMT. The price they quoted was a mix of airline rescheduling charges (higher than what is mentioned on airline website) + fare difference (however, our previous flight fare was higher compared to current flight fare) + EMT charges. They totally skipped informing about EMT charges earlier and provided no reasoning for fare difference.
We asked them to cancel flight and refund airport tax. They got back saying, it was a no show so no refund can be provided. How can an open ticket be no show? They only adviced us to convert flight to open ticket to avoid a no-show.