Why bother?

Something that really annoys me is what happens when I go on holiday. Before I go, I always make lesson plans for each lesson that substitutes have to teach for me. When I come back, I find that 90% of the time, the subs haven't followed them (in most cases it appears that the subs didn't even look at them). So, I do all that extra work for nothing, but would get told off if I didn't.