I had similar in DXB where I couldn't check in online, and instead checked in at the desk at the airport. Firstly the staff were adamant I'd already checked in. When I maintained I hadn't they issued me a BP for DXB - LHR but not the LHR - BRU sector. After getting that issued I noticed that my DXB - LHR boarding pass was for Club World (result - an upgrade) but that the BAEC number was incorrect. They then changed that for me and gave me a new BP.

It was only when I got to the lounge and was asked about checked bags and whether my wife had any (she didn't - I am not married and was travelling alone) that alarms bells sounds and we realised there was a glaring c*ck-up somewhere. It transpired that there were two of us with the exact same name on the flight. My alter-ego was travelling with his wife in J, while the real Geordie405 was in WT+

When I got to the gate I had to surrender the Club BP and be given a new (correct) WT+ one for myself. From speaking to the CSD on board after departure he told me he was very surprised that such a mistake could happen at such a small outstation such as DXB with only 2 or 3 flights a day but that if I had made it on to the plane with the Club BP then he'd have allowed me to remain in Club World and that I would not have been sent back to WT+