I had a great support from Office 365 Security team this week. I was constantly attack via phone.
I had a great Support from the German SecurityTeam of Office 356 this week (Mr Demtschenko). He made great efforts to help the attacks I was getting by phone and investigatet that the number that called me was suspicous, plus, the method they used (looking up one´s Computer ID) was faked by telling me some number that is installed in all Computers with Micrososft installed. A good advice to prevent such Information is eventually to inform customers ahead, in what cases one should be suspicious to fraud or phishing as for instance, calls from "Microsoft Headquarter".