Here's all you need to know. The Owners Corp is liable – end of story.
Your EC/building manager needs a serious wake-up call. This is their problem and they have to fix it pronto. How dare they say you have to pay for this yourself? When a similar thing happened in the Horizon building a few years age they rehoused all affected owners in a luxury hotel and did an industrial clean of their apartments.
Now, your building manager can either do this the easy way or the hard way. They can get on to this pronto – no arguments, no delays and no compromises – or you can take them to the Supreme Court (forget the CTTT) and demand damages for the repair and replacement and the cost of a proper clean-up, plus damages for the stress they have subjected you to (which is rising the more they delay), and all court costs.
In fact, I would get a lawyer to draft a letter saying exactly that (and include their legal fees in the demand).
This is a disgusting (in so many ways) abrogation of the owners corporation's responsibilities and they should be grateful you aren't a more demanding owner.
When they're done cleaning up your apartment, they should take a course in strata law and OC responsibilities. Let us know how you go.