Gillybob
Enough really is enough, now that the letter has arrived from the attendance monitoring officer, it's time to go to the very top!
Write to Justine Greening, the Secretary of State for Education, enclose maps with your DGD's route to and from school, bus timetables, copies of all correspondence between your family and the Education authority, anything at all that is, or may be relevant.
You've tried talking to the 'monkeys', now it's time to speak to the 'organ grinder!
There comes a time when a battle has to turn to an 'all out war' and I think this is it!