Q525: What can be done about children who play ball games on a grassed area/verge even though there is a no ball games sign?
Playing ball games despite a no ball games sign could be a breach of a by-law. You would need to contact your local police via their 101 number, but you must be aware that unfortunately it will not be a high priority matter for the police. You could also try the local council.
See the website in related information to find your local authority.