Mtn
Unable to CAP my line

I called the call center for MTN, with the intension of Capping my line. I was told by the call center agent, that this service is no longer avalible, as it "compramises" the customer! what B/S! as a customer of MTN, i should be able to add or remove services and I as a customer, should be allowed this service! why is it that others like vodacom and Cell C allow it, but not MTN. How are we to monitor our bills as the agent told me to, if we have phones like the iphone? which charge data costs!! Come on MTN, this is just an excuse to slap us with huge bills, that we are trying to prevent!!!