Over promise and under deliver due to incompetence

On the 5th of August I logged a complaint with Rashani Govender in a role of Business End user supervisor. Details of my query were given to her and she promised to investigate or retrieve recordings of my discussion with a call centre agent. After one week I made a call to Rashani for progress and I got an excuse instead. A promise was made to investigate and that I'll be called within 3 working days and once more she failed to call. I had to her again and received another excuse. She also informed me that her manager Thegan Naidoo has worked out refund for being overcharged amounting to over R 2 500.00 which will be refunded within a week. I waited for a week and no credit was made to my account. I have sent Rashani more than 7 emails and requested for her manager email address. She gave me an incorrect email address which was returned by mailMarshall. I have requested her to forward email to his manager and copy me 3 days ago and has not been done. <br> <br> Can someone senior that care about customers service contact me and sort out this complaint.