repeated calls in regards to possible "iCloud breach"

I keep getting calls on my phone identified as from caller "Apple inc". These are calls about a possible breach on my iCloud account. On 7/6/2019 I got the first of these calls, which I answered to. It sounded suspicious. When I asked if I could call them back, suddenly the call was dropped. No one called me back for the next 2 days. Then today (7/8/2019) I started getting repeated calls, caller identified as "Apple Inc"; I have not answered to these calls. Are these real calls? if not, what can I do to stop it?