Over charged and they still want more payments

Had a garnish order of R7749.49 starting from September 2012, my employer was deducting R688.47 monthly from my salary. According to my employer this was paid-up. But today when I just received a call and statement from my HR stating that this was not paid-up according to the attorneys but below the statement on the 30/04/2014 its written that \paid-up with client: legal fee collection interest correction". <br> And on the statement there 4 payment that are not reflecting and the dispute is also on my statement. I feel like they just over charged me with too much outsource interests after each and every payment. And according to my calculation they over charged me.<br> I tried to call the office today they said I must send them proof of payment. But where am I going to get them since it was a garnish order with my employer. They said I still need to pay R3017.79. I need correction on my account."""