What is kmarts shoplifting policy on items under $5.00? (michigan)?

I was detained at my local kamrt store tonight. short version: I was with my 8mo old son and he was in his car seat, which was inside the cart. I was there for about an hour and was originally looking to purchase some shorts for summer. being that they have a godawful selection, i proceeded to other departments (shoes,automotive,grocery) when i remembered that i needed double edge razors($4.89) for my vintage shaver. anyway, i make my way over to the blades, and place them inside the cart. Fine. then i roll on over to the grocery isle (remember, my 8 month old son is in the cart with his huge carseat) I get to the cookie isle, when i notice my son (who was unstrapped at the time but laying inside the seat) was moving around and grabbing for things. i became concerned that he may just grab the blades and even tho they were in a package, i took precautions anyway, and slid them underneath his seat so that he didnt see them. Well, i grabbed my cookies, and looked around a bit longer and proceeded to checkout. I became distracted by some other customers conversations about the wait in line (the slow cashiers and only 2 lanes open in the entire store). I finally was up to pay for my cookies and did so. I left the store with my son still in the cart,and a smile on my face due to my cookie purchase. well, i get to the exit and the doors open and i see this little short, fat thing in my face identifying herself as kmarts "loss prevention" official. Loss prevention? no, you mean "loss my damn mind"!!...she confronted me about the razor blades, and immdiatley i remembered what she was talking about. I was soo shocked that i actually slappede my forhead with my palm,cause i had totally forgot about them in the few minutes that transpired between picking them up and buying them. well, this 4 by 4 chikc grabbed my cart with my son in it and told me to follow her in to the back of the store. she knew i wouldnt go anywhere if she had my son with her . I was in shock and followed her to a dimly lit room with an uncomfortable chair and a Dorito stench. the room smelled like open . like they had been sitting there for hours watching people in an enclosed room on a monitor. well, all kidding aside, i tried over and over explaining what happened but she replied" cut the bs", "you know what you did"..well, after that i just gave her all the info she wanted (except ss#). the more i tried explaining i guess, i started to sound guilty. anyway, she made me sign a form that said someting like "civil something", and told me that i would have to pay back up to 10 times the amount I "stole"..she also told me that she see soo many women conceal smaller items in their kids car seats, so i shouldnt even bother explaining it anymore...in other words, iam guilty and just pay the fine. Now iam expecting to be extorted by some half witted law firm/collection agency capitalizing on my error and demanding payments totalling about 50.00....so, can i contest this? it this right? I swear i would NEVER steal anything...ESPECIALLY with my 8 month old son in tow!! has this ever happened to anyone???