Wisconsin Child placement child support question- please help court tomorrow!!!?

My boy is 16 months old. Since the day he was born I have been very active in his upbringing. I had him for 70% of the time if not more 4 the first 7 months. Which was doented with all receipts totalling almost $2000. Last October in court it was ruled joint placement/joint custody. The mother argued she was not happy only $40 a month, even though I him more(which I do not understand) due to her unhappiness mediation was ordered. Due to the cost of mediation and a new understanding from her that I do have him alot, we put off mediation. I got calls from mediation asking for papers to be turned in but the mother insisted it was a waste of money. I also stopped doenting everything due to a pretty regular routine, and fairness from her. few months ago I took a 2nd job requiring her to have him more, with no complaints from her. I even arranged for babysitters on my regular days and she kept him anyways. I was served with paers by her 2 change placement! This is unfair- what do i do?