Vodacom always disappoints

I phoned Vodacom on the 10 of this month and tolled them my contract was coming to and end and that I wanted to cancel it. I then got connected to the cancelation department where I explained what I wanted again and was helped by a lady that said everything was in order and the number will go over to pay as you go when my term is done.

Yesterday I just had an inkling to phone Vodacom again and make sure the contract has been canceled, as I've had many problems with them in the past. With out disappointing, the contract wasn't cancelled and this lady now told me that I phone in to early to cancel the contract, it has to be exactly 20 days before the contract ends. When I phoned the first time no one told me this. Vodacom please go listen to your recorded calls. So now the lady said she will process the cancelation again, but it will only be affective from end of May. I feel this is unacceptable, I did everything right, but still Vodacom wants to find a way to get an extra months worth of payments from me. I just had to cancel a line with Telkom, and had much better service from them, non of this nonsense. This is why I've also decided to move all my numbers over to Telkom.

Will someone please look into this and rectify the mistake. I did what I needed to do and I not willing to pay and whole month extra!