Welcome to Flyertalk and welcome to the BA forum.

I can't recall this happening before, and it's the sort of thing I would have remembered. At this stage you best raise a complaint via
ba.com/complaints
take photos and keep the card safe. BA should be able to recover the funds and to pay you separately, But I suspect this is going to take a long time to resolve. If you go back via SFO you could try asking at the desk, in case it's a known local issue which they can deal with there, but I have my doubts.