"Dell Support" keeps calling me

Someone claiming to be dell support has been calling my mothers cell phone and our home phone.

They even knew my sisters name, (my sister is the one who first set up the laptop by the way)

they said that my pc had suspicious activity that resembled a malicious virus and he asked if I was aware of it. My sister told him " I had my tech guy check it out and that he said it was fine" and he said "okay" and hung up

i then contacted someone on dell support live chat on dell website and they said it was a new service offered by dell? is this true. And my pc is perfectly fine, and if this is a new service then is there way to turn it off? its sorta creepy.