my personal loan balance not keeps going high

i have a loan with nedbank, whch i deafaulted on due to being unemployed years ago. then when I started working nedbank sent a man to my work place who made me sign a document saying that nedbank is giving me another chance to start paying again. we agreed on an amount of R750 which i had been paying since June 2014. i paid this amount till november 2015 when i had personal problems and i defaulted. in december they didnt debit so yesterday i went into a branch and called their legal department to find out what is my balance so i can settle. the amount they gave me was schocking. it was as it i had never paid a cent towards this loan. the lady who assisted me said that i started paying them in July 2015 and i disputed that. she couldnt give me answers so she said she was going to request a statement and email it to me so i can see the calculations. i gave her my email address and 24 hours later i still dont have that statement. this is very bad service and not to mention cheating customers. i need help on this