Hi!
We can certainly understand the inconvenience. Unfortunately, it does not seem possible to block a specific area code with this model. You would have to add the full telephone number. However, the phone call rejected will still be forwarded to the voicemail service. As an alternative, you might want to look for third-party call block apps that may offer additional features and can be downloaded from the Play Store app.
We also recommend that you add your phone number to the "National do not call list", which can help reduce the volume of calls. Additional information about unwanted calls and the registration to this list can be found here: http://crtc.gc.ca/eng/phone/telemarketing/