How do I stop Telus telemarketers from calling me

I am a Telus mobility customer and soon after I became a customer I started receiving multiple calls every week from Telus telemarketers trying to sell me different Telus mobility phone packages. Its by far the most frequent telemarketing call that I get. Every time that I pick up I tell the agents to put me on their do not call list, but they just keep calling me. Mostly the call ID just says Alberta, other times a number from Rocky Mountain House. Its so frequent that I am considering changing providers in the hope that it will stop.