Posting this in case it helps others, as it took me 4 phone calls and 3 months to resolve.
I use the tfl app on my iPhone (IOS). I registered a new credit card as my old one expired. I was using it for travel with apple pay ie I tap my phone on the readers rather than my credit card.
The journeys never showed on my app. I couldn’t claim for a card clash over charge (user error here!) as the journeys were not displaying.
I won’t go through the wrong advice that the tfl helpline gave me, as it won’t help anyone. But if this happens to anyone else, the correct procedure is:
Use your actual card for one day’s travel on tfl. Wait 2 days for that card info to be fully loaded and registered on the systems. Then you can use apple pay and it will start picking up your journeys. It will also show all journeys in the past year. They will display on your tfl app as a different card used, so it is helpful to login to your account on the website (not app) and rename your credit cards so the apple pay card shown has a different name to the actual credit card – otherwise you won’t be able to see which journey was paid with which device/ card.
Apparently, this shouldn’t happen. It should recognise apple pay as the card and display your journeys accordingly. Occasionally it doesn’t and the solution is to use the actual card first.