Harassing me to settle a zero balance acc

A day or two ago I received a call from a man stating he is calling from Edgars wanting to know how much I'm going to settle on my acc. Told him that to my knowledge my balance is zero and I haven't received a statement - this appears to be a trend when my balance is zero. He promised to email me a statement, still haven't received it. Then he goes on that I need to still pay the Club fee and demand to know how much I'm going to pay - if I'm not willing to confirm an amount he is going to type R100 on the system. Today I get a sms stating I have to pay Edgars R100. Here is my question to Edgars - why don't you go an harass the people that owe you thousands of Rands and are NOT paying their accounts. I am seriously considering closing my acc since I barely use it any way and every time I try to book a movie ticket it says my card is invalid. Truely pathetic customer service.