Pandoc is open-source software, maintained by volunteers working in their free time. Please keep that in mind when asking for help.
The first place to go if you have a question about pandoc, or if something doesn’t seem to be working properly, is the pandoc-discuss mailing list on Google Groups. (The mailing list is also mirrored on gmane.) This list has over 1500 members, and more often than not, someone will answer your question quickly.
If you think you’ve found a bug in pandoc, you can create an issue on the github bug tracker. But unless you’re sure it’s a bug, it’s good to raise the issue on pandoc-discuss first. See the guidelines on contributing for some suggestions about how to write a useful bug report.
Suggestions for enhancements to pandoc (for example, new formats, options, or structural elements) should always be discussed on the mailing list before an issue is created on the github tracker.