The spam calls are few and far between… when measured relatively against the fucking sales cold calls.

Avoid publishing important people’s direct phone numbers and force calls through a full time secretary or group of secretaries - if sales people call on direct lines notify them this is a private line and that you’ll block their number for repeat offenses. Make a note of the caller, company, and number - if they already have a strike refuse to do business with them… watch in glee as you slowly build up a black list of all telecom providers.