keeps calling and harrasing

I work in the telecom industry and this appears to be an operator service company that provides service to hotels, hospitals, prisons and payphones. The reason it shows up as a dallas number is that is where the operator center resides but calls could come from any where in the states. I had a couple calls from my cousin that I did not accept but my guess it was from a jail or prison.

Rcvd call ignored it they did not leave message

I missed a call from this #, can't call back ,

When man called he left a message and said it was regarding my daughter, so when I called it back I asked what company it was and the lady was very rude and would not give no information. Is this legal?

Continous unsolicoted calls with no message

wondering who this is