Talk to the school and find out why they have done this.
Talk to the other parents and find out how they are finding it.
Talk to your dc and their friends and how they find it.
Talk to the bus company to find out why they got rid of a bus stop outside of school and changed the route.
Log your typical journey times and details for your trip to school before this all started.
Log your different journey times to school now - both bus and walking.
Figure out what your journey to school would have been like with the new bus timetables but the old system at school.
Give the system a couple of weeks to settle down as everybody gets used to it.
Then look at all your information, see if people are still experiencing the same problems as they were when the system was introduced. If they are then go and talk to the head teacher. Or organise a meeting for the HT to talk to you if there are lots of you that want to discuss this with them (and so they can't fob you off with 'nobody else has a problem with this').
Unfortunately I would guess that you are stuck with the bus route changes, but it might be something to use to talk to the HT about how their changes have had even more impact than they would have done previously.
If you still don't get any response then write to the governors - and then the local papers.
Have they changed things at the other end of the day - are they expecting you to pick up five minutes earlier?