From what you've said: your Dad is angry/aggressive and you fear for your Mum's safety if she goes back home, he is refusing to speak with the memory clinic and isn't taking his medication. Did the social worker call you back? If not I'd suggest contacting the social services emergency safeguarding team, on the basis that your Mum is at risk if she goes back home. They can contact the psychiatric crisis team if necessary. I understand your reluctance to get the police involved by contacting them directly but it isn't clear whether you've tried ringing 111? Explain to them that your Dad is a vulnerable person who is not taking his medication. If he is angry/aggressive towards them then they may call the psychiatric crisis team or police for assistance but your Dad needs to take his medication, or be given a change of medication, so has to be assessed. If the emergency services are involved then he will get the help he needs and as that seems to be the only way that your Dad is going to be assessed and given his meds then I don't see what other options you have other than those that have been already suggested. Unfortunately it often takes a crisis for someone to get the help that they need, and the situation isn't going to get any better for your Dad and Mum if things are just left as they are so you need to be proactive. Did you try ringing the helpline again, or the live on-line support service?