Contract expired, bank continues to bill me.

I took out a loan with Capitec in Jan 2012 and had 48 months to pay it back. I signed a debit order for them to deduct from my personal account that is not with Capitec. The first month they deducted was Feb 2012. The copy of the contract clearly stipulates that the contract ends on Jan 2016. I have never missed a payment. I was surprised that they debited my account again in Feb. When I called, they informed me that I still had 1 more moth to pay. I instructed my bank to reverse the debit order and they did. Now after going to Capitec to query this, they now said I owed 2 months and interest. How is that possible? The contract ended in Jan 2016. The lady called Puleng who helped me over the phone insisted that I still owed because the contract hadn't finished and that I had to continue paying. She said the error was made when the contract was drawn up. That is not true, Puleng is not counting properly. Below is how I paid the money back. Now I ask that the bank remove any monies 'owed' to them by me because I paid all 48 instalments.<br> Feb 2012 to Jan 2013 (12months), Feb 2013 to Jan 2014 (12), Feb 2014 to Jan 2015 (12), Feb 2015 to Jan 2016 (12), which is 48 months. Please resolve