False positives have happened on occasion. If you know you did not do anything wrong, contest the ban. Sadly with Blizzard's customer support being what it is, you will most likely receive a cookie cutter "we have now confirmed that the initial decision was correct" type response. It might take a few attempts to get them to hear you out, but keep trying. Be politely and explain what you were doing. Some have had luck getting incorrectly applied bans overturned.