There is no option to do this and Rogers the greedy company they are wants an additional $5 a month for a 2 second task to simply block the number. I contacted support regarding a number that has been calling myself and other Rogers customers that I know, and instead of blocking the number globally (a telemarkettiing scam) they want each of us to pay $5 a month to block the number.
I don't think so... sure let's all change our phone number again and again, and hope that a different number isn't calling that one as well, oh wait, keep paying the $5 a month and they'll stop that for you. Pathetic that Rogers has the infrastructure to block these unwanted calls but they charge the customers a ridiculous fee for a one time command that never has to be looked at or monitored again.
go into settings->call settings->voice call->auto reject and add number.
you can also go to your call logs and long press on the number, and scroll down in the pop up menu to “add to reject list"
This works, and if you want a free app solution, CallFilter does the same thing.