The National Do Not Call Registry gives you a choice about
whether to receive telemarketing calls at home. Most telemarketers should not
call your number once it has been on the registry for three months. You can
register your home or mobile phone for free and your registration is effective
for five years.
If they do call you after you've been registered for 3 months,
file a complaint at this Website.
https://www.donotcall.gov/default.aspx