Daddy by default

I am in the doctor's office the other day and they asked if I had received the mail they were sending to me. When they showed me a copy of what they were sending, I was furious. My baby's father is part of her life, but I am her sole caretaker. I put him on the medical forms so that we could have his information as well, but that I was single. It seems that they use the address I gave as the "child's address" and by the daddy's name by default. What?!@? Can't they read that I checked that I am single? Don't they notice that I am the one paying the bills and bringing my baby to the doctor? Is society so behind the times that single moms have to always 'clarify' this? We have more single parent families in the US today than ever before and they need to catch up with the trend.