Overcharged

I took out a 24 month contract on the 12/3/2014. In February 2016 I gave notice to terminate this contract on its anniversary date 12/3/2016. This was done.On the 12/3/2016 I received an sms telling me the contract was cancelled and that I had been moved to Prepaid. All correct.<br> However, I now get charged for the full month of March 2016. When I took the contract out, I was pro rata'd the first month 13th - 31st march 2014. So when the contract ended on the 12/3/2016, I should have received a pro rata'd charge from the 1st - 12th March 2016. I want the difference credited to my account immediately.<br> This is theft. The amount owing to me is: R102.50<br> <br>