FWIW, there are services one can use that can certainly help.
For example, I use Abine's Blur service, which provides a masked phone number that forwards calls and messages to your actual phone number (and allows you to block/unblock any number from calling you with just a click), masked disposable private credit card numbers, and unlimited revocable anonymous spoof email addresses that forward to another email address. This puts the power back in your hands, so if/when a bad-acting vendor tries spamming you, you can block or delete the info you provided to that vendor, thereby preventing the bad-acting vendor (or whomever they may've sold your info to) from ever being able to reach you again. As long as you never give out your 'real' contact info, it's remarkably effective.