Hello! Have a bit of a situation I'm hoping others have experience with (couldn't find anything with a few searches) since the call center agent just shrug it off as "nothing she could do".

I have a current award booking SCL - MAD with IB. Two agents tell me on the phone that they can add another leg (i.e. MAD-OPO) as long as (a) I pay the change fees and any other cost resulting from that last leg booking; (b) There's availability for the MAD-OPO leg with Avios.

Now... they can't see availability but I can (of 5+ seats) on my online (ba.com) search.

Both tell me that there's no availability. Both tell me they're searching for MAD-OPO only and not SCL-MAD-OPO (which I'd guess to be the problem first).

The last agent tells me there's nothing she can do. Anyone has any ideas on why this happening, if I have any recourse or I'm stuck with having to buy a separate (much later so I have time to connect in MAD) ticket?

Thanks!