I‘m pretty sure, it isn’t.
Go check the TOS of any public transport yearly subscription models and they will certainly have the exact same clause.
I had to pay a penalty fee for terminating my yearly public transport subscription in Berlin early.
One example of the consumer law being applied is in regard to drip pricing, which was commonly used by airlines and hotels:
https://www.accc.gov.au/consumers/online-shopping/drip-prici... https://www.accc.gov.au/media-release/airbnb-and-edreams-giv...
Pricing rules, in this case Partial Pricing, are quite clear:
If you promote a price that is only part of the total price, the total price must also be displayed at least as prominently as the partial price. This means customers should be able to identify the total price in the advertisement at least as easily as prices for any component parts.
https://www.accc.gov.au/business/pricing-surcharging/display...Also relevant: subscription traps: https://www.accc.gov.au/media-release/accc-warns-consumers-t...
I am unfamiliar with consumer protection in DE, and publicly owned services like the railways may have special pricing legislation, but new EU harmonized laws are being introduced for digital services: https://www.linklaters.com/en/insights/blogs/productliabilit...
Sadly, the EU system prevents any member state from having stronger protections.
For subscriptions there are already strong rules about clearly indicating the total price, and the amount that is fair for early termination: https://www.osborneclarke.com/insights/distributing-games-in...
It's past time that consumers in the US realized their utter lack of power as individuals against corporations, and their collective might. The 'dark patterns' in online commerce, car loans, mobile payments etc are really 19th century business practices that shouldn't be accepted anymore.