I'm getting calls at work and the number is 966509653061

The number I received was different... +966-509-xxx-xxx That is the format for international calls from Saudi Arabia. Your phone bill may only show the North American 10 digit format, and thus misrepresent the number, also truncating the last digits. Try looking at the caller id on the phone itself. There is a 966 North American area code, but I bet your call is from Saudi Arabia. I omit here the last digits of the calls I received as I am in the process the tracking the issue. My caller seems to be a complete imbecile, be it that they are speaking Arabic. I have no messages left on my voice mail, but they seem to try back periodically, like one of their brethren is going to magically materialize on my end. Perhaps get a call blocking device or service.

Calls me up and does not speak English.  They have called me 3 times now and left messages on my Voice recorder.  I don't understand what they are saying.