This application form:
http://www.hdb.gov.sg/cs/infoweb/doc/su ... ation-form has all the T&Cs the landlord must meet to sublet his HDB to you. Might be worth a read, especially:
1 Flat owner(s) and their proposed subtenant(s)/occupier(s) must satisfy the above stated eligibility requirements for the subletting of the flat. Flat owner(s) must not have committed any infringement at any time prior to the submission of the application or at any time thereafter.
2 The flat owner must obtain the HDB’s prior written approval before commencement of subletting.
5 Flat owners are not allowed to sublet the flat on a short-term basis. Each individual subtenant (or authorised occupier of corporate subtenants registered with HDB) must be in continuous occupation of the flat for at least 6 months.
6 It is a serious breach of the lease to sublet the whole flat without the prior written approval of the HDB. HDB may take action to repossess the flat. The flat owners and occupiers will also be debarred from applying for or being included in any application for any HDB accommodation.
So based on these four clauses:
a) did you get proof of the LLs eligibility to rent the flat to you?
b) did you pay stamp duty and get a receipt and/or acknowledgement that the stamp duty had been paid?
c) HDB is quite explicit in stating that they will not interfere in landlord/tenant disputes. However, they may take action against the landlord if the Landlord's lease (from HDB) has been broken. But apart from repossessing the unit, it doesn't help you any. However, the threat of you going to HBD and causing a whole pile of pain might make him negotiate quickly.
d) If the agent was yours (i.e. not the landlords) and was paid to act on your behalf and they didn't get proof of LL's eligibility to rent to you, or sort the stamp duty, I would kick up a fuss with the agent, their employer and the CEA.
Now, here is the bad news:
21 HDB’s approval for the subletting of whole flat will be automatically revoked upon the transfer of flat ownership
So the HDB does not consider you a party in this once transfer of ownership has taken place (in fact, you're not a party in contract with HDB at all).
My course of action would be to gather all letters, agreements, stamp receipts, eligibility letters etc and then go look for somewhere else to live.
Based on your actual losses, write to the landlord and copy your agent, explaining what you expect to get: refund of deposit immediately (no 14 days waiting!), refund of stamp and agent fees, cost of moving company to relocate, cost of installing lights/appliances anything else you are out of pocket for, maybe increased rental costs, even new beds if the old ones don't fit the new place. Singapore doesn't award punitive damages on the whole, so make sure your claim is totally backed by receipts or quotes.
Next, take all that info to the free legal clinic at your local People's Association Centre. Check noticeboards there for legal clinic times. Sometimes all it needs is a letter from a Pro Bono lawyer to get a party in breach of contract to fall in line. (If you're SC or PR you might also be able to get free legal advice from the Singapore Law Society). If your agent screwed up, ask them if you have a claim against them too!
If you don't like their advice, or if the landlord then refuses to negotiate or accept your proposal, starts a Small Claim Tribunal, good for claiming up to $10,000. You should write out the entire sequence of events and correspondences and have all the paperwork reviewed by a third party (or the free legal clinic).
Hope that helps. Do come back and let us know how you get on.