Vielleicht hilft das noch ein wenig weiter:refuse:-
To indicate unwillingness to do, accept, give, or allowHe refused treatment.deny:-
To declare untrue; contradict.
To refuse to believe; reject.
To refuse to recognize or acknowledge;They denied the prisoner food or water
In many cases, they can be used interchangeably.I'm sorry we have to deny your request/refuse your request.
If you're using it before an infinitve, use refuse: I refuse to discuss it any further. I refuse to consider it.
If you use it before a noun:
If I refuse, someone is offering it to me, but I won't take it. I refused the money she tried to give me.
If I deny, the word that comes next is the person
that I won't let have [whatever it is that's being denied]. I denied you [the satisfaction of seeing me cry.