Chubb Termination

I cancelled my Chubb contract at the end of April 2015. I was informed that there is a cost of R320.00 for the removal of the radio device fitted to my alarm system. I enquired if I could remove the radio and deliver it to the Chubb office thereby saving on the R320.00 fee. I received an email from Hermien Dirker confirming that I could do it myself and deliver the radio to her by the 30.04.2015. I removed the radio and took it through to Hermien on 30.04.2015, she gave me a job card confirming the receipt of the radio. My bank account was debited two months later with the R320.00, I contacted Hermien and she said that I must go to my bank and reverse it and that she will make sure it does not happen again. I then received a statement in September showing that I still owed the R320.00. I was then debited again in October. I was furious and sent an email to Hermien, she apologised and informed me to go to the bank again to reverse the entry. She said that the credit will be passed, I now receive a November statement still reflecting that I owe R320.00. These people are thick as I have a job card signed by them that the radio was returned by me and they did not have to come out.