I'm not being insensitive or piling on. I just don't want this to ever happen to you again.
'Cut from railing'. They cut your lock? Try the 'two U-lock method'. They cut the railing? That's sucks, but it can happen in any 'common area', particularly one that's out of sight and unvisited for lengthy periods. Get the bike inside - there are ways: indoor racks that lean against the wall*, bikes that fold as thin as 15cm, etc. Once you get the bike inside, try the two U-lock method.
*Googling around I found everything from fancy 'Scandinavian style' leaning racks to DIY ones made from scrap lumber or PVC pipe, many of which could go against the wall above your sleeping mat in your 13 m^2 apartment.
Last edited by tcs; 02-15-19 at 09:29 AM.