I received a letter to respond with a written answer in terms used in chapter 802 of the Wisconsin statutes. What is this and is this a open court that I can attend? I am being sued by a credit card co.

Chapter 802 just states the rules for WI courts in suits such as this.

You can Google Chapter 802 and find out the rules. You need to send the court a letter of your intention to defend against the suit so a hearing will be scheduled.