Thanks very much for the help, calling the general line worked well (I was put on hold very briefly but was able to talk to someone within a minute or so).

In case anyone is curious, my flight to LHR was delayed and I was guaranteed to miss my connection to SJC. Fortunately the agent I spoke to was able to change me to the SFO flight so I'll still make it home tonight. I know I could have waited until I arrived at LHR, but having things sorted out ahead of time is much less stressful.