Amazon’s Echo calling doesn’t let you block people

Amazon seems to have made a significant oversight in bringing voice calls and messaging to its Echo speakers: there’s no way to block communication that you might not want. So long as someone has your phone number and the Alexa mobile app (which requires an Amazon account), that person can place voice calls, record voice messages, and send text messages that will reach both your Echo device and Alexa app. They’ve got a direct line to a speaker in your home.
As of now, there is no way