Secretary of Nicol Davis and Associates have no professional manner of communication

I have been contacted by an M Fortune who works at this firm in (Tygervalley, Cape Town, Tel: ********** ) regarding a optometrist account of 2013 that has not been paid by my medical aid, so the optometrist handed the account over to them for collection. I was not aware that the medical aid did not pay the account because I never got an statement of some kind. When Fortune contacted me the first time I asked her for which optometrist is this account and she said DR Stallman in Paarl. I was not sure who DR Stallman was because I have seen several optometrists in 2013 as I was struggling with an bad eye infection. My problem is the attitude of this Fortune woman who does not know how to speak to a client. When I could not remember the optometrist she asked me with lots of sarcasm in her voice "how many optometrists did you visit in 2013 mr Levens?" When she called me the second time I told her I can afford to pay R100 a month as I am a single mother with no financial support. She insisted that I pay more than R300 a month through a debit order. I told her that is not going to happen as I will do an EFT of R100 each month. When she called me in July I told her I will pay a R200 monthly, but after I checked all my expenses against my income I decided to do a payment of R100. Then I received an email from her insisting that I pay the other R100 as soon as possible. I did not reply on the email because she told me in previous conversations that it is a generated email process they are using so they will not get my reply. I think she tried to contact me on my cell a few times but I could not answer because I was busy with my job that pays my salary. Today she called me on the landline of our office(open plan) and asked me with that awful tone of sarcastic voice when I will be paying the R100. I told her in a calm voice that the payment or R100 was all that I could afford at this moment. This woman who does not know me at all then told me that I should get my priorities straight. That is when I lost my temper and hung up on her. I have really had it with this woman who has idea on how to communicate in a professional manner with clients. I am trying to meet her halfway but she is rude. If she is not happy in her place of work she should find her another job because her way of working and talking to people is going to get her no where.