Still havent recieved my Refund

I have received an sms on the *** form African Bank. I went to the Branch at Middelburg Mall the day after with my ID and a stamped bank stamen as per the request in the sms. the lady there was not able to assist me but have taken the papers and said she will process it soon as the system is online. to date nothing, I have mailed and contacted the call centre's and mailed bank statements and copy of my ID to them more than once. went back to the brunch on Saturday and still they were not able to assist me and the lady that tried to help me the last time doesn't now where my papers is and what she have done with it. it has been almost a month now that I have tried to get my refund and in the meantime they are getting interest on my money.