I need to setup a call center so I can setup agents to make phone calls across Canada to market our services.  I am trying to figure out the most reliable and cost efficient way to do this?

I am currently paying for two phone services and neither seem to have a actual call center application.  Ring Central and Vodia both give me the infrastructure to let agents share outgoing and incoming phone lines depending on their shifts and they both will distribute calls to the free agents.  

I need to be able to setup various sales campaigns so the agents can read which service we are about to promote and also setup things like: the step by step sales scripts; quick reference scripts that the agents can read to deal with potential customer objections; listening in on agent calls; quick help from a senior marketing team member; agent notes on potential buyers; call backs; and transferring of calls to onboarding team or remote support team.

Has anyone customized Zoho Desk or Zoho CRM to do this sort of thing and if so would they be interested in selling the custom module?  Alternatively, if anyone knows of a Zoho marketplace addon that actually can do this sort of thing but is not cost prohibitive to a small company that is trying to grow their service?