bad service

Some time last year I get call from this woman Mrs Carollisen who sold cartridges to me... after 1st invoice was paid I get another call from her for another 2 cartridges,, well after this was paid and another invoice I told her we are no longer interested and that she should stop sending cartridges she agreed and said this will be the last order, I called her again after the last delivery and still she said yes she will close the account. a few weeks ago I get the another call from her the same woman Ms Carollisen saying that there is still cartridges left after she told me she will close the account and delete our company details from there system at the last conversation. She went on about if I don't take it the cartridges, the company wants its 25% discount back. After our heated discussion I spoke to a Mr Victor Langa.. supervisor or someone in a senior position. I explained the whole situation with him. I asked for voice recordings and he said there are no recording this after this women told me that all calls are recorded. I mean who does business like that? This VIATEK company should be reported. I refuse to pay for any discount.