The openreach database entry was created (after a survey) with the wrong PCP in it, though they probably believed it was right at the time. The wrong PCP is closer (about 10m away), while the right one is about 100m away.
More explanations in the topic
here, but some details were within a semi-related post
over here.
By the sounds of it, your best route is probably now with Openreach, the CEO or Chairman (as used by someone commenting on the first thread above), either directly yourself, or with the help of your building management people. Presumably the building management have some records dating from when the work was done - but if not, you should emphasise to BT that your ISP was unable to help.
It is entirely possible that BT are right now - your line is EO - and were wrong to change the database to show fibre is available. If that is the case, then your complaint is really with the building management for not ensuring that Openreach converted all the lines over to the PCP.