Today is very difficult to get the information about quantitys of Mailing, SMS and Push Sent. Yo need to get a report for mailings, search push into push reports and go to Mgage Campaign Manager to get the totals for SMS. The API GETMAILINGSENTFORORG / LIST / USER give you agreggated information about each mailing sent (Emails, SMS and push) but into the response you do not get a channel indentification, so you must recognize manualy.