Complaint about dishonest information from mrp mobile

I want to complain about the mrp mobile as i have recieved a call from 1 of their agents that told me mrp is having simcards for their customers which they give out to clients for free.I have asked the consultant that called me that day if she was sure these sim cards are for free and she confirmed they are free to my surprise when i went to pay my account there is a R100 that is part of my monthly payment from April of which is that simcard i was given which i dont even use.please help me to get my money back as i have been **** to and they betrayed me.i feel so sabotaged and cheated on by mrp mobile.