Continued debit order after termination of contract

After 8 years with Neotel i terminated my expired contract on the 16th of August 2017. They carried on debiting my account. When i stopped it with the bank, neotel just changed the amount. At present they charged me R500 for none usage. They claim that i have not given notice. When i started to give notice at the beginning of August they told me that i need to send it to: ********** . Now they telling me that this was the wrong e-mail, it just should have been: ********** If i sent it to the wrong e-mail??? Why was the mail not returned and since neotel is one of the company's which records every conversation, why do they not go back an listen to the conversation when their consultant gave me the so called wrong e-mail????? I had a great experience in the early days with Neotel, but this obviously changed since they have been taken over by Telcom. I suggest to everybody to stay away from telcom, sine they are up to no good and start cheating their old customers once they terminate their contract!!!!!!!!!!!! The bad part is that they insist on a debit order, knowing that they just need to change it by a few cents to slip trough the bank account. My debit order was the past year R149, they changed it in December to R149,65. That's what i call THEFT!!!!!!!!!!!!!!!!!!!!