See link and message 7 from a moderator of the forum, who I would suggest has more knowledge than a CS rep.
Apart from anything else, why would you think BT would keep your storage space/contents on their servers for free when you are no longer acustomer!
What has been said on this thread is correct. Your Cloud data is deleted 30 days after the broadband is ceased. I'm sorry if you were given incorrect information when you called BT.