I am flying to Spain next week from SFO. I booked my roundtrip flight through Priceline, just basic economy fare. For the first leg, SFO -> LHR, it is through Iberia but operated by British airways.

Is there anyway to upgrade to a higher class with my AAdvantage miles for just that leg? Who would I call? I tried calling Iberia, they told me to call priceline, who told me to call Iberia back ?

Any tips are greatly appreciated!