So what I thought was a blocked sink turned out to be much larger problem

[Pat Vegas]

Ooof! I don't really know how blocks of flats work, but if the problem is with the building rather than your pipes, is there not some way of recouping money from the building owners or something?

That's what I am doing now but they are quite stupid.
they will say I didn't call them but they don't answer the phone.
apart from that I quite like the place.