Stop harassing my family and sending me sms

My Standard bank credit card acc was handed over to Lgr attorneys last month they called my mother and disclose all the info about my debt which led to my mothers blood pressure to be high,and the agents were they never trained that u don't disclose debt to the third party cause I know my rights very well as a debt.Last week I called them to make the arrangements that this month I can only afford to pay R300,due to the funeral that occurred but the lady who and was rude and said they will serve summons if I don't pay R600 and what confuses me I never made an agreement with them that I will pay R600 every month,so they must stop harrasing my family and come up with the amount I can afford monthly.