Account Recovery Farce

My 78 year old Nana’s email has been signed out over some ‘suspicious activity’ which she has no idea about. Using the correct password isn’t working and none of her authentication methods are working despite being correct. I’ve submitted recovery forms on her behalf but they keep coming back as rejected. This is becoming beyond ridiculous and she can prove who she is, etc, etc…. If someone could please just call us. A real human that she can speak to or I can speak to. Surely they could go through security questions and we can regain access. It needs sorting and she needs access to her emails. Please help Microsoft!!!