over three months and query not sorted

I was promised a credit to my account by monwabisi in early December 2014, that has never happened. I got a call from Xoliswa Matele, who said that she would resolve the matter. I then got a call from monwabisi who said the he knows all about it and will get back to me as to when the credit will be passed. Never heard from him since. I have sent numerous e-mails to him and to Xoliswa but no response. I don't know what to do. I have been shoved from pillar to post since October last year. I appeal to vodacom, if my query is not going to be sorted, kindly cancel the contract so I can move my business to a company that can actually help people