I have had success getting dupes removed this day. Bing used to remove dupes through support but now require it through "suggest an edit".
When we report them, sometimes they are taken down other times not. I believe actually writing something along with suggesting an edit helps tremendously. Put your reasoning in there, well documented, on why the listings are spam.
Also, if you're reporting a practitioner listing (ones that Bing sources from NPPES, vitals, etc.) I'm not sure if they will take them down at all.