Tracking managers to confirm employment

This morning my manager was contacted with regards to an employee. The caller, Maria, called my manager's direct line and asked her to confirm if a certain employee worked there and if the person reported to her directly. This was confirmed, however my manager's details are private and they are not given out to anyone, let alone people in the SA market! DMC was contacted by myself and I spoke to Maria and asked how was it possible that she speak to my manager regarding a certain employee and how did she acquire my managers details, to which Maria responded that this was done through a \tracking"system! I explained to her that this was ******* and her manager's details are required"