Obviously there were a lot of people who got a call from this number. Maybe after the seventh person everyone should stop saying they got a call and not write anything if they do not have any useful information. I do not think anybody who checks this website cares when or how many calls you got. They want to know where and why the calls are coming in.
This person called me twice and I answerd one call the person said "hello" and I started speaking an annoying made up language and they hung up and they never called again. My advice is if they annoy you. You annoy them.
You may be stalk or under surveillance.Pay attention what is going on outside around you, mimicking or staff like that.
By the way, no need a reason for surveillance.