But have you asked BA if there is any kind of residual credit towards different dates/same city pairs?
I had a similar situation on the cheapest available BA fare. No refund, no changes to flight segments. But the actual dates could be changed for a fee and fare difference.
BA's cheapest I class fares from London to San Francisco do indeed have rules that state
Originally Posted by BA rules
CANCELLATIONS
ANY TIME
TICKET IS NON-REFUNDABLE.
.
.
REFUND OF UNUSED TAXES FEES AND CHARGES PAID TO
THIRD PARTIES PERMITTED. ASSOCIATED CARRIER
IMPOSED CHARGES WILL NOT BE REFUNDED
.
.
CHANGES
ANY TIME
CHANGES NOT PERMITTED.
NOTE -
A CHANGE IS A DATE/FLIGHT/ROUTING/BOOKING CODE
CHANGE.
The approx. £238 in taxes paid can be refunded, but need to fly the route booked on the time booked or lose the ticket value. For ticktes originating in the USA, the ability to hold credit is common, but not from UK
Since no miles can be accrued, if unable to travel, getting back the £238 would make cancelling still better than just leaving the ticket
Unsurprisingly, AA has the same rules on its cheap business fares from London too