Incorrect device ordered, no feedback!!

My mom ordered an iPad Mini with wifi modem contract for R239 a month, they incorrectly gave her the iPad Air for R500 pm, without asking her if the change was fine with her. She went back to them and they acknowledged that they made a mistake, but do not intend to fix it. After numerous calls, emails and a call to the call centre, (over a period of three weeks) we still do not have an answer!! They informed us that they are waiting for a response from the head office, but no feedback is given. This is really frustrating and after going through all the correct channels, I am now forced to leave a complaint on Hello Peter.