School Bus Woes

My children take the bus because I pay taxes for the service.
My daughter's bus stop is a ten minute walk.
My son's bus stop is a seven minute walk. Since he is still in elementary school, I must met him at the bus stop at drop off time. He is the last child on the bus at the last stop.

Drop off times may be different if the bus has less children on it and does not have to stop on stops. This at times, makes the bus stop earlier.

I cannot see or hear the bus from my house so sometimes, I can be on time, and wait, but no bus comes.

I walk home (it is a big hill to walk up or down). There is a message on the phone machine.
It is the school saying that no one was there to met him, he was brought back to school and now I must go pick him up.
Sometimes, I have to find a ride to do this.
I get to school and the office says they tried to call but there was no real answer just the machine.

My response is that of course there was no answer because I was waiting at the bus stop seven minutes away.

Why do they call or tell me that?
I take my cell phone with me now to the bus stop and I call them when the bus is not on time or my child is missing.
At least we all get a daily workout walking the hill.