Vodacom Business Cancellations Department

We have been trying to cancel business contracts that haven't been in use for years as well as create a new contract for one of our staff. I have emailed the agent who first made contact , Jeslin Palany to no avail, when I try call she is unavailable , they have said they will get someone to call back on the landline on many an occasion, but I have had no calls and no responses to any emails. The only reason I could think is because they are trying to avoid us cancelling so they can continue billing us. The next move will be to transfer our large business contract to another provider.