looking for suggestions on how to proceed...

I'm looking @ booking DFW-IAH, Friday May 2nd on AA. There is lots of availability in Y showing to the rest of the oneworld alliance partners, except BA. US reservations sees the space, AA sees the space (obviously), Qantas sees it...just not BA.com, which instead insists on routing me on US via CLT.

How do I go about booking this flight with Avios. When the call center was in Florida those agents were wiling to try "long selling" for the most part. I'm not getting that from the UK agents at all (Just being told I'm retarded in a polite way and how Airlines only release a set # of seats for awards, and that they must all be taken).

Anyone know what language/phrasing I can use to press the issue with the UK agents?

thanks in advance.