They called my cell today and did not leave a message.

Calls at least once per day.  Telemarketer.  Rude.  Canadian drug sales.  Swears at you when you ask them to remove the number from their list.

Get numerous calls from that number among others that leave no message.  Time consuming but maybe worth the time.  Make a note of the number and e-mail to your State Attorney General.  Do the same w/ unfamiliar e-mails.  Worth the time and effort ?  Who knows, but if it cuts only a third to half of all the senders availability to call / e-mail several times a day, I'd be satisfied.

I am getting 2-3 calls from 564-645-6498

Calls every few days, never leaves a message.