Don’t hesitate to contact us:
Forum: discuss.graphhopper.com
Email: support@graphhopper.com
For OpenStreetMap data you can change the data on your own on openstreetmap.org and after 2-6 days our routing services will consider these changes. So if there is a street missing or a barrier is passable, you can edit this data when you have local knowledge at openstreetmap.org or put a note there so that others fix or investigate it for you.
Read more at learnosm.org if you are new to OpenStreetMap.