Six months ago I booked a fare with Arangrant (an OTA that at one point had a kayak integration). It had three legs, A,B,C, and A and C are long-hauls.

Soon thereafter there was a flight schedule change by the airline. Since the schedule change was significant, Arangrant was offering free modifications ("wow!" I thought). I didn't do anything immediately as I considered options.

This whole time, I could log into the airline's website and see the new schedule, and I still had a confirmed ticket on A,B,C.

Last week, I called Arangrant and requested a change to the time of flight B and a change to the date of flight A. They said they would check with the airline about the possibility of making that change and get back to me for final confirmation.

Soon thereafter, the airline's website reflected the change to the time of flight B, but there was no more flight A. My confirmed ticket is now only B,C and departs from a different continent.

The airline says they're unable to make any changes but could confirm that Arangrant deleted the first flight leg.

Arangrant is claiming they made no changes to the ticket, but obviously that's false since B was adjusted exactly as I requested as soon as I got off the phone. Arangrant used to be claiming that I still have my original confirmed ticket A,B,C but I finally got them to admit the first leg was deleted.

All customer service emails and phone calls go to this one poor chap who can't actually touch tickets. He can only refer my "requests" to the ticketing team who then "requests" things from the airline. He says they've been making these "requests" all week. I find that hard to believe since they were able to delete my flight A instantly but can't reinstate it after a week.

What are my options?

ps. no need to ridicule me for booking with Arangrant, I already feel it enough