Bruma fiance

I always receive a call from Shereen that my Bruma Finince account was handed to them and I asked how much do I have to pay she said R1602 then I paid R1000 the next month I receive an sms saying I now own the R801 and she call I said why is it going up always there reason she gave me was not vailid today she called me again asking when am I going to pay I said for now I don't have money and I will be able to pay R300 month end she then said I own them R950 Like really, I said to her I am not going to pay them at all bcs when ever I pay the amount goes up, Could you please assist me regarding this matter.