bought a cheap A fare return flight during the promotion earlier this year and wanted to change the inbound date before I took the outbound flight - A fare rule allows this but would need to pay £300 plus fare difference. Both F and A fare were not available (either sold out or not visibile to BA agent) at the time I requested the change. Only J fare was available, which I would have been happy to take. But the BA agent said I cannot change to J fare even J fare cost more than A fare. She just said the system didn't allow her to make the change although she didn't understand why that was the case as J fare cost significantly higher than A fare (£8000 return in J vs £2800 return in A I paid vs normal £5400 return in A). I tried 2 times with different agents on 2 different days and I got the same answer. Does anyone know why I could not make the change in this instance.

I went through A fare rule and I do not see any restriction except the new fare value has to be equal or higher than the current fare. Please see the exact fare rule I saved when I booked the ticket.Thanks for your help.

CHANGES BEFORE DEPARTURE CHARGE GBP 300.00 FOR REISSUE/REVALIDATION.
NOTE - WITH THE EXCEPTION OF TICKETS CHANGED IN THE US ANY PENALTY FEE MUST BE COLLECTED VIA AN EMD. REFER TO SPEEDBIRDCLUB.COM OR BATRAVELTRADE.COM AND YOUR GDS FOR INSTRUCTIONS.
--------------------------------------------
CHARGE APPLIES PER TRANSACTION - PER PERSON FOR ALL PASSENGER TYPES. INFANTS WITHOUT A SEAT - NO CHARGE.
--------------------------------------------------
A CHANGE IS A DATE/FLIGHT/ROUTING/BOOKING CODE CHANGE. NEW RESERVATION AND REISSUE/ REVALIDATION MUST BE MADE ON THE SAME DAY.
--------------------------------------------------
REISSUE MUST BE MADE THE SAME DAY AS CHANGE OF RESERVATION BUT NO LATER THAN SCHEDULED DEPARTURE TIME OF FLIGHT BEING CHANGED. OTHERWISE THE TICKET WILL ONLY BE VALID FOR REFUND IF APPLICABLE.
--------------------------------------------------
WHEN MORE THAN ONE FARE COMPONENT IS CHANGED THE HIGHEST PENALTY OF ALL CHANGED FARE COMPONENTS WITHIN THE JOURNEY APPLIES.
--------------------------------------------------
--- REPRICING CONDITIONS ---
REPRICE USING ANY FARE TYPE EXCEPT ERU AND EOU. HIGHER FIRST CLASS FARES MAY BE USED FOR REPRICING CHANGED AND UNCHANGED FARE COMPONENTS SUBJECT TO AVAILABILITY AT TIME OF CHANGE. A. WHEN THE FIRST FARE COMPONENT IS CHANGED THE ITINERARY MUST BE RE-PRICED USING CURRENT FARES IN EFFECT ON THE DATE THE TICKET IS REISSUED. B. WHEN CHANGES ARE TO BOOKING CODE ONLY IN THE FIRST FARE COMPONENT AND RESULT IN A HIGHER FARE THE ITINERARY MUST BE RE-PRICED USING HISTORICAL FARES IN EFFECT ON THE PREVIOUS TICKETING DATE OR USING CURRENT FARES IN EFFECT ON THE DATE THE TICKET IS REISSUED - WHICHEVER IS LOWER. C. WHEN THERE ARE NO CHANGES TO THE FIRST FARE COMPONENT BUT OTHER FARE COMPONENTS ARE CHANGED THE ITINERARY MUST BE RE-PRICED USING HISTORICAL FARES IN EFFECT ON THE PREVIOUS TICKETING DATE OR USING CURRENT FARES IN EFFECT ON THE DATE THE TICKET IS REISSUED - WHICHEVER IS LOWER.
----------------------------------------------
NEW TICKET VALUE MUST BE EQUAL OR HIGHER THAN PREVIOUS AND MUST COMPLY WITH ALL PROVISIONS OF THE NEW FARE BEING APPLIED.