bad customer service i have encounted at mrpmobile

Good day, I have a complaint about a bad service I have counted at MRPMOBILE and that they allow their service providers to make a bad way to advertise their products. I was offered a mrp sim card by a guy, he said it was for free. It is a reward for being a good and loyal customer, and since I have an account with sheet street I thought maybe he's genuine and he mentioned that am not gonna pay anything for it. I asked him several times if there will be any payment for the sim card, HE SAID NO! To make the long story short, I received the sim card and I called mrp within the seven days of delivery. when I call, I was told that its not FOR FREE , I WILL PAY FOR IT. I THEN ASKED THE LADY TO CANCEL IT. SHE DID. and she never mentioned that there's airtime loaded in that sim card already and I must use it even though I cancelled the contract. So that even if they require me to pay, I pay for something I used. and then last week I received my statement and the connection fee for R129 and mrp sim of R100 was listed on my statement, of which I don't understand cause I've never even used the sim card, now I was told to pay for it. when I made cancellation 7days within delivery , how is that fair? and how do these people operate? cause from what I know if you done the cancellation within 7days of delivery, you don't pay for anything. so how do I pay for something that I did not use? and I was not given enough information about this .

I am really not happy about the way they handling this matter. For some reason, they take it light as if I am crazy for not wanting to pay for the airtime I did not use. Thank you