OnePlay haven't added any new games since early December (it's the end of Feb now). Maybe the rental side is coming to an end? The games still seem to be available, so perhaps just play them for a year.
I think that's one for support, I can't see any reference to that issue online. I believe you need to keep a valid credit card with them for the duration. I had no problems activating or cancelling during my subscription.
I've activated it and everthing but since getting this I can't get any game to work, shows up as activation failed
Denmark are in the EU, so they should be fairly responsive to any payment issues (and there's always your credit card company)?
WARNING: I signed up because of this deal, they have charged me the $1, then an additional charge of £51 !! On top of which, when I try to play 'Firewatch' I get an error saying 'no license'. Avoid, avoid, avoid. If you've signed up, check the 'payment history' tab in the client as mine had rather more entries than I had expected or authorised.