I take it OP is not a very experienced traveller, has no status and redeemed the ticket with BA Executive Club.

There's not much more OP could have expected. In case of IRROPs he is at the mercy of the operating airline unless he has the ability to sort himself out or get the travel agency to do so. Tthe travel agency in this case is BAEC, which as Blue is a fat load of good. Go claim BA for the GBP 520 and the two most expensive phone calls as entitled under UK261 as suggested above.