Why can't cancellations be as efficient as signing up a contract

<p>I opened a month to month data contract with Telkom for cell no ********** 923. As I no longer required it, I asked for it to be cancelled and was told to put in writing, which I did. The letter of cancellation is dated the 7th of July. We are in September and I am still being billed for the cancelled contract. I am totally fed up and will not be doing any further business with these chaps.</p>