I have just intalled the app on my LG TV and signed in. It tells me that I have to start a free trial and that after the period I will be charged.
I already have an account via BT.
What do I do?
Reading your post again it sounds you may have done this already.
Perhaps try another fresh NOW App download and after its been downloaded, unplug the power to the TV for a minute and try signing in again.
Also if no luck, maybe post over on the BT TV Community Forum, where maybe another BT TV customer had the same exact problem.