Airtime not credited to account

On the 7th of august I purchased two R50 airtime vouchers via internet banking. Only one was credited to my phone. I called the 808 call centre, I was advised that I needed to send an email to customer care. I received a response from the 1st consultant Palesa, who sent me back to 808 call centre, with a reference number. on the 20th August I called and spoke to the 2nd consultant Mathabo, I emailed her my proof of purchase and received another reference number as the 1st query was not even logged. She promised that the correction will be done in two working days. Nothing was done. I sent an email again to customer care, 3rd consultant Mmapule asked for my details and I have never heard from her again. This last Friday I called 808 again I spoke to 4th consultant Thandolwethu, I sent her all the email corresponds, logged a query for me again and also promised that all will be rectified by Monday. Today its Friday nothing has happened. I have heard about the bad service MTN is giving it clients and all about airtime that goes missing. I have proof of that and not one person from MTN has the decency to provide me with an answer or honour their word.