Dual CALL problem

I bought a 2nd SIM last year Oct/Nov and tried to activate the dual Call function. It has never worked since then despite calling the call centre so many times it is just not getting resolved. Today I went on the online chat and after explaing my problem and explaining how it's supposed to work to the agent, the agent just disconnected and I was left hanging. MTN this is unacceptable, please and I repeat PLEASE, PLEASE sort it out. I need this to work for business purposes and it has already cost me a LOT!!! If there is false advertising on your website then please remove the section. Agents need to be properly educated about the different services, I should not be explaining to an agent how a service is supposed to work. I am disappointed with Lesego for disconnecting when she/he could not provide answers!!!