If you put only leaves and nothing else in the composter, they will take a significant amount of time to decompose. You need to add a mix of 'browns' (leaves) and 'greens' (grass clippings, kitchen waste like fruit and veggies). The compost needs to be turned at a minimum every week to get airflow throughout and to make sure everything is composting and not just the bottom.
The council collects green waste. Some stuff never rots down so they get. I have weeds in my grass so never put it into compost...2 big bins 1 for leaves 1 for green stuff. Dry as a bone...Will water & dig over