Hi honey,
There is nothing, absolutely NOTHING, more important in this world than your child. I had several bad experiences with childcare in the past myself, and I learned to break things down to the bottom line--my children above all else.
Whether you are younger or older--you are still a mama now, and your gut will tell you when to stand up for your child. I have learned the hard way that when it comes to the safety and care of my loved ones, I am much more concerned with them than some stranger's feelings. I am a polite, caring person. I am tremendously patient. I hold the door for strangers and pick up seniors that have fallen on the ice.
When it comes to my kids, I have no problem with telling a Dr or babysitter to kiss my a** if they are not acting in my child's best interest. I politely declined to have the nurse remove my son's clean diaper and onesie for weigh in. I got dirty looks, grumbling and general bitchiness out of her. Oh well...That's a negligible difference in his substantial, chubby weight, and a huge difference in his comfort in the cold, unfamiliar office. My husband has gotten used to me being "mama bear"--he didn't even look embarassed...lol...
YOU are the mama. Further--their lack of attention to the children indicates that someone's precious child is going to suffer at some point. Telling them calmly that there is a problem could be seen as a duty to perform for the health and welfare of others.
Take a deep breath, my dear, put on your warpaint, and don't ever back down when it comes to your son.
Best wishes and blessings to you