Bad service

My account was debited with R4900.00 after I told Discovery that I cannot afford this, I'm a pensioner. I have sent all my documents to Discovery, it took a while because I don't own a computer and had to get someone to do it for me. The money that Discovery took was money I got from my children for food I now have nothing. I have asked that someone please contact me. It has been 1 week, why do I need to complain before anyone listens?