I used this:
https://www.britishairways.com/trave..._br?eId=191001

and this:

https://www.britishairways.com/en-br...ting-documents

I was rejected twice and then accepted. I am convinced this is a robotic process that is not relevant to the validity of the claim. I say this because I needed the TP at the end of my year, but my family, who travelled with me on the same fligh, did not need the points. So I made a claim only on behalf of myself (which was a separate PNR in any case) and jumped through all the bureaucratic hoops to get my points. Yet my family were also awarded the points without making a claim, but this came about 4 weeks after the flight.