You may want to see this page
Remember that you cannot unban yourself from channels (that defies the point of a ban). Ops can ban you for whatever reason they like. IRC Operators will not unban you if you think a ban is unfair.
Also, if there was a kick message specified, read it and take note of what it says, it might make it easier for the op to find out why you were banned. It may also give advice on what NOT do to next time.