Put your phone number on the National Do Not Call Registry and that will stop most of the annoying phone calls. Your registration is good for 5 years. We get random calls when a company calls with Random Digit Dialing. Those can't be helped and they are few and far between. See the link below and it will answer your questions about this service and provide you with registration if you so wish. Good luck!

https://www.donotcall.gov/default.aspx