Even if you consider your verbal request (and his inferred approval) as a form of contract then by my reckoning "a couple of months" would take you up to April. So either way there is no contcat and it looks like he is within his rights. That's only my opinion, though, and it would be worth getting a more authoratative opinion.
I'm surprised he took so long to make his request. Assuming you just ended a two year lease, your landlord is losing money every month if you are still paying your original rent. The housing market is up sharply in the past two years, and he could make more money renting to someone else.
Since I've had a problem with my landlord and used Asiaxpat for advice I;ve seen you respond to certain issues so would you mind responding to my problem. See Rights of Tenants. I would appreciate it.Thanks associates.