Repeated calls from XXXX XXXX XXXX, each time I answered the call, they would hang up. After XXXX calls, I called back and discovered it was a collection agency. I asked what debt they were collecting and they said they could not find a debt linked to my phone number. They stated they would remove my number from their database. I checked my credit report multiple times with no debt collection indicated. Two days after the multiple calls, I received another call with a hang up from this number. I called back and they asked if I knew anyone by the name of XXXX or XXXX who could be reached at this number. I told them no and explained the situation from the other day. They continue to call my phone repeatedly during work hours.