Tell us what is wrong.
Bug reports are the most useful thing you can send, because most failures are specific to one site and we cannot see them from here.
Or write to us
Goes to a person, not a queue. Use it for anything the form does not cover, including rights and takedown notices.
What makes a report useful
The address of the page it failed on, whether you used quick or deep, and what you expected to get. That is almost always enough to reproduce it. Screenshots help but are rarely necessary.
If content of yours was copied through this service, or you want your domain blocked from being captured at all, that is covered in the terms.