So to summarise- Your ticket NYC-BOM-NYC allows no-show and changes for $500.
- You were quoted fare diff of $1000 (+ chg fee $500) to change for another date. Even though you online saw that the fare you purchased was available for your new dates.
- You now want to travel BOM-NYC only and was quoted $1200 in fare diff (+ chg fee $500).
My comments to these points
2. Are you sure that you saw the exact same fare online and that you searched for the exact right dates and exactly the same route? Some examples that might explain the fare difference:
- The fare you saw online was lower that what you had purchased, and you can't downgrade your ticket. The next fare available above yours was $1000 more expensive.
- The fare you bought is not a public fare and can't be upgraded to the public fare you saw online.
- Availability online and with the agent you spoke to is different.
- Your fare allows upgrade to certain fares only, and not to the one you saw online.
- TK call centre incompetence.
3. Here you are asking to change a round-trip ticket starting in one area to a one-way ticket starting in another area. One-way tickets have completely different pricing and are with most airlines (especially long-haul) more expensive than round-trip tickets. So generally my guess here would be that TK's quote is correct. One thing is odd though: TK have published several one-way fares BOM-NYC that aren't that expensive (provided you travel in economy class) so with that in mind the great increase in price doesn't make sense, unless the flight you wish to change to has very low availability.
Two questions
1. Did you try HUCA?
2. Is it possible to refund your ticket instead?