It's probably too late now for them to have any more flowers. Perhaps they just needed some fertiliser? However, if you pot them up and trim them back slightly you can probably over-winter them indoors and hopefully have better luck next year.
Do you have them in plenty of sun? If that's not the problem, maybe you have over potted them? They won't flower if they are busy filling the pot with roots. Don't spoil them with too much feed either. Hope this may be of help. Regards H.