Councils disregard letters that repeat chunks of material copied from others, such as the paragraphs in C42's post.
Only useless ones. Ours includes in reports to councillors "487 said this, 123 people said that, 4 people said the other, and here's a precis of the unique comments".
Planning issues are not however decided by a count of objectors or supporters but by planning law considerations. If one person raises a valid point that's just as good as 1,000 people raising it.
Non-planning, ie policy, matters
do depend on the number of people supporting one side or the other. Provided, of course, that these people are resident in the area and write to their own councillors - no councillor is going to take quite as much notice of someone who isn't one of their own voters, now, is she.
Re the original post. I see no mention of any appeals. If no appeals have been made, then why not? If repeated appeals have been made and failed then there's not a lot of point in putting pressure on the council as it's the inspector who's going to make the decision, and I know of no way of putting pressure on the inspector.