Same with mine. I am looking for an answer too.

I think I should have let them rest,in the dark around Sept, but they never died back :(

mine never died back either. they are in the conservatory the 2nd year just leaves and then last year in May they produced flowers. Just fed and watered as the rest of the house plants.

I've repotted at the backend of last year, but they are already pushing thick roots from the bottom of the pots. I'm completely befuddled! :(

they are in a 3lt pot as the one you get when you buy them is far too small.
Put them outside in the summer they enjoy the fresh air just keep them watered.

Thanks SBG,I'll have to see to them after I get back from hols at the beginning of April. I'm sure they will be OK until then.