I had a really awkward situation last week when I travelled again.
Despite the early hour I got there 15 minutes before the train and explained at length the issue to the chap on the gateline, who insisted I had to touch-in at the barriers in front of platform 4. Would not budge. TFL previously insisted I would not be refunded again as I had 'touched in for the heathrow express'. I did ask if I could look for a 'standalone reader' but he wouldn't let me through to check.
With less than 2 minutes left until the train left I had to jump the barriers and get on the train.
At Heathrow I had the same issue. I'd have happily paid for the fare then and there if there was a way of deducting it correctly from my Oyster card, but of course there wasn't at that stage and would have resulted in a maximum cash fare, so another circumvention of the gateline needed.
Really not my preferred option nor a stress I wanted at 5am in the morning... but the only one remaining given TFL and GWR's stance.
I have to do this journey every 2 weeks, what's the chances of them resolving? I would much rather just pay the correct fare than risk running into a RPI.
I explained it at both gatelines so they have all the information necessary to escalate and resolve.
Are you really saying that BA could see details of a flight taken 20 years ago?
If you're a BAEC member, absolutely - they dug out flights from decades ago to tot up 'Lifetime Tier Points' when it was introduced. I believe it also extends to non-BAEC members as well, there's a very interesting thread over on FlyerTalk re: SARs to BA.