Moved into rented property not as described

[filthiestfis]

2 weeks ago my partner & I moved into a flat via an agency. The problem is that on the day of moving in,when we got to the agency's office to sign the contract and get the keys, the agent told us that the landlord had made a mistake and that 1 of the 2 sofas in the living room was a "prized antique" which the landlord wanted back and therefore would we have a problem with the landlord retrieving the sofa before we moved in. I replied that I did object to it being taken away as the sofa was included in the viewing of the property & on photos & description on the agency website.
The agent is acting on behalf of the landlord and as such we have not had any contact with landlord, but he said he would speak to landlord to try to find a replacement, which was fine by us.
Two weeks have passed and we have heard nothing from the agent. I can only conclude that leaving the prized antique sofa in the property was done deliberately to improve its perceived value and that, most likely, the landlord has been using the sofa trick everytime a new tenant has moved in. I stand by this because within 2 hours of us signing the agreements someone came round the still empty property and took the sofa away, demonstrating that this was a premeditated act.
Unfortunately, we were cornered on the day of signing as we HAD to move out of the previous property (the agent knew this well) and the man with van was already booked. All the arrangements were made for the move to take place, otherwise I would have sought a legal opinion.
Legally where do we stand? Can we push for the landlord to replace the sofa he took away? If he says that he wont replace it where do we seek help to solve the matter?

[KARL]

I would think you have three options, all assuming the sofa is in the list of contents (inventory): 1. Insist that a replacement is provided or else the rent is reduced commensurately (in court this would almost certainly be a very small sum to be reasonable), 2. Insist that the rent is reduced (if you are not after a sofa, ditto) or, 3. declare the landlord in breach of contract which then becomes null and void and you promptly move out. By my reckoning none of these are called for or merited but you should press for the replacement sofa on principle, one of same potential usefulness value. You are entitled to the stated inventory to match the stated rent, but my guess would be that taking legal action would be seen by many/most as particularly litigious if not b-minded. It strikes me as unlikely that the landlord would deliberately leave the sofa in as bait - how many would choose the flat simply because of the sofa ?

[filthiestfis]

KARL: Thanks for your reply. The living room is large and without that sofa there is a large gap left. Usually a sofa comes with an armchair but here there is only one sofa.
Regarding inventory we have not received any.
So...?