Loan repayment more than 10 years

I app**** for a homeloan in 2013 and i got R76000 ,and the first installment was in july 2013 , for 72 months . I am still paying the loan with the balance of +- 20k . This January marked 133 months ,and when i email them ,the response is that the balance is determined by terms outlined in the contract ,of which the contract said 72 months .The repayments are on stop order .