For anyone interested, here was my situation.
Rec'd postcard for 5k/10T in Sept, read online about 5k/5t and registered for that instead on 18 Sept (only in the one promo).
Abt 10k points posted b4 23/24 Sept but then no more. Started to read this thread and wonder what was going on.
Left it for a while, spending as normal (and got an extra card for my wife for the upcoming Xmas shopping). In Nov rec'd another postcard inviting me to be on Xmas promo. Called Amex to express concern I got a promo postcard when I should be on 5K/5T promo already - they verfied that I could only be on one promo and I was on the better one anyway with points to be paid in the "near future".
Early December I got the letter stating ineligible to enrol in MYREWARD and put back on MYBONUS 5k/10T. Read on forum many getting this letter and started to draft a response to Amex in line with Ts and Cs but before I got to send I got the 2nd letter stating "admin error" and I was put back on 5K/5T. Just to be sure called AMEX and first CSR said I wasn't on any promo that he could see at all
evil
. Finally got him to speak to MR and they said I was on "correct" promo.
End December got remaining Sept points and what I figure was abt 50% October points so left it and see what would happen. End Jan/start Feb got points for Nov/Dec - also spot on at 50%.
Called Amex last week and explained to CSR abt my calc of 50% points for Oct/Nov/Dec and told them of confirmation letter of 5K/5T. Faxed that in and now one week later I have all remaining points I believe I was owed.
Moral of the story - stick to your guns especially if you have the "admin error" letter and provide it to CSR/MR as proof. I didn't need to involve the FOS, but understand many may not be so lucky.
Good luck to everyone... and thank god for not having to check this thread and my MR balance 3 times a day anymore