Unprofessional Agents

This morning I received a call from Edcon and the lady on the other side was so rude, sarcastic and unprofessional. I hope that it is true that the calls are recorded and that isn't just a line said to us for nothing. I owe Jet stores R 3294 and my last payment was made in February of R 100. I have been unemployed since September 2014 and when I can I pay the R 100. I tell this lady I will only be able to pay R200 at the end of the month because I have started a new job. she sarcastically laughs and tells me I am not serious, when I never worked I paid R 100, now that I work I pay R200? she doesn't even know how much I will be earning, what my other responsibilities are besides Edcon. We continue the rude conversation then I hang up telling I will pay the R200 end of May. she calls me back I ask how I can help her she tells me the calls are charged and she just wants to charge me more, she called me 4 times after and sent me 5 sms's of the same thing just so that I can be charged for all that? now should I really be paying the bill or this lady should??? is this how Edcon trains their staff to call people as many times as possible to make money out of that? No telephone ethics!!!