Upvote:2
I see no indication that the site still exists. This is probably because there is no reason to use such a service.
To get your money back, you can either use the online form if you have a bahn.de account and booked your ticket there, a paper form (available here, or sometimes handed out in a delayed train), or any service center at a station.
There is no wiggling around like with some airlines. If you have a valid claim, you'll get your money.