There are two issues here: the copyright and the model release issue. You need to send the infringing company a cease and desist letter such as:
Dear [name of infringer]
It has come to my attention that you have made an unauthorized use of my copyrighted work entitled [name of work] (the “Work”) in the preparation of a work derived therefrom. I have reserved all rights in the Work, which was first published in 1999 on mycompany’swebsite.com, and I have registered the copyright.
Your work entitled [name of infringing work] and which appears on your web site at yourinfringing.com, is essentially identical to the Work and clearly used the Work as its basis. [Give few examples that illustrate direct copying and/or unfair use.]
You neither asked for nor received permission to use the Work as the basis for [name of infringing work] nor to make or distribute copies of it. Therefore, I believe you have willfully infringed my rights under 17 USC Section 101, et seq. and could be liable for statutory damages as high as $100,000.
I demand that you immediately cease the use and distribution of all infringing works derived from the Work, and all copies of it, and that you deliver to me all unused, undistributed copies of it, or destroy such copies immediately, and that you desist from this or any other infringement of my rights in the future. If I have not received an affirmative response from you by [date] indicating that you have fully complied with these requirements, I shall consider taking the full legal remedies available to rectify this situation.
You can change the copyright owner info to that of the magazine you gave permission to if you really want to and it will probably be scary enough to get them to stop. If they don’t respond, get a lawyer to send one.
The second issue is model release permission. They can’t just use your image or that of your child willy nilly:
"Publishing an identifiable photo of a person without a model release signed by that person can result in civil liability for whoever publishes the photograph.
Note that the photographer is typically not the publisher of the photograph, but sells the photograph to someone else to publish. Liability rests solely with the publisher, except under special conditions." en.wikipedia.org/wiki/Model_release