EK's system has been known to do this. MMB remembers your status at time of booking even if you then end up changing tiers prior to travel. There have been some posts about this in the past. My daughter had exactly same occurence as yourself but as Zol said above when she turned up at the airport with about 8kg over basic allowance and fluttered her eyelashes, showed them a print from MMB, etc., etc., it was all to no avail - she was blue and they knew it (as did she) so she left some stuff with us rather than ask me to pay the extra for her ...