"Wonderful" tech support

Four days ago I got banned for the reason " due to Ninja in dungeon"
An hour later I wrote to tech support the whole story, without screenshots, but they obviously have access to at least the chat and information about the character (his talents, spec and clothes).
The main thing in this situation is that for 4 days tech support has not given any answer, although I asked to give it officially.
What should I do? How can I get justice if I am banned for nothing, and they do not want to read the complaint?

Somebody reported you with screenshot or video evidence need rolling an item, and winning it, that wasn't an upgrade for you for the role you were assigned.

Ban appeals are slow as they are the lowest priority.