UNABLE TO CANCEL CONTRACT - poor service

I phoned vodacom costumer care to have my contract cancelled on the 20th June as it expired on the 15th July. The lady told me that I have to phone on the 1st or on the 15th of a month to cancel it (I found out later that that was a lie as the terms and conditions of vodacom states 20 working day notice). I tried to phone at the 1st of July without any success, tried almost 20 times, so I decided to go to Tambotie Mall Vodacom shop to have it cancelled. The consultant told me that I can only cancel the contract on ***. I phoned that number and stated that I wanted to cancel my contract. I received and sms from a TOBI vodacom chatbot and cancelled the contract. It was confirm by TOBI and it stated that a person will contact me which never happened. I tried to phone vodacom several times during the month to confirm the cancellation but can only use their selfhelp services because according to them, I phoned them to many times and my number was blocked at their call center, which is unacceptable because if someone phones that many times they are suppose to know there is a problem. A debit order was taken from my account on the 29th July. I phoned the call center from my daughter's number (because my number is still block at their call center). The lady confirmed that the contract was not cancelled and that she will cancel it. I refuse to pay for an extra month because Vodacom do not know what they are doing. I never experience so poor service. Please think twice before taking out a contract with this company.