My friend has had to put up with a similar situation for a year or so now. Despite calls to the police, the Housing Association, keeping records, taking photos etc etc, the Housing Association have now closed their file on the case as my friend is not prepared to be a named complainant. Unless she allows her name to be used, the HA will not proceed with any action against these people. Unfortunately, the HA cannot guarantee that eviction will be the outcome even if action is taken against them. My friend is, therefore, obviously reluctant to let her name be used, for fear of repercussions. It's a vicious circle, and she and you have my sympathies.