this very near pushed me over the edge

Received a $3800 bill incorrectly stating that I had under declared my income for 6 months, when I spoke to centrelink I explained that I only worked one day a week for 6 months then I was working full time, the person I spoke to said that is happening a lot and changed my reports to properly represent my earnings and said the debt was cleared. Got an email 3 days later stating that I still owed the debt, after contacting my employer from that period (6 years earlier) to get pay slips, I was told they no longer have them and they would not produce them for me. After speaking to the centrelink representative I explained my situation, and it was reduced to $400 because apparently I still claimed wrong for one period, I didn't totally agree with it, but I got the feeling that they weren't going to stop until I either gave them some money or went to court. This happened over a week, during that time I was extremely stressed already from what has been a horrible year, this very near pushed me over the edge. I haven't received any real confirmation from centrelink that it's settled, it's been a month now, and I honestly am just waiting for them to do another backflip, its a very anxious time