https://community.spotify.com/t5/Desktop-Mac/Windows-support-1-888-639-4788-Windows-Support-Phone-Number/m-p/3796800
+1-888-639-4788
These Scammers use some techniques to get their number displayed on google, etc. so that people can call them.
Found 3 more
they publish their toll free number over the internet almost daily
https://wiki.scn.sap.com/wiki/display/ABAPConn/Microsoft+Support+Number+1%3D800%3D522%3D6899+Microsoft+Support+Number+KACAGMTeqjkqx
+18005226899
https://wiki.scn.sap.com/wiki/display/ABAPConn/microsoft+support+desk+phone+number+1-%28800%29-653-1176+microsoft+it+support+number
+18006531176
http://www.princed.org/wiki/User_talk_1877-578-4644_microsoft_support_number_1877-578-4644_microsoft_phone_number
+1-8775784644