Signed a Contract that is not correct

I signed a consolidated loan with old mutual in 2013, and I am paying monthly as arranged.<br> We received a statement from them and if we calculate the outstanding balance the contract should be ending in December this year. My repayment is quite high on this loan.<br> Now when I contact the call centre they tell me that the contract ends in 2018.With the calculation they are telling me that I owe then over R300 000. The initial loan amount taken was not a lot. When we took up the loan at the Alberton branch we told the consultant who is no longer with the company that the loan must end in 2015. <br>