I have a eVouhcer from last year, I would like to move to the next class of service by either using Change flight or Upgrade options - both are showing on BA but credit card is the only payment option. I've been told I can use my eVoucher for this but I must call. Well, it is impossible to call... Question: If I went to the British Airways ticket counter in Phoenix (it's open for 5 hours a day) - could they do this for me at the counter?