Pathetic service

I have had quite the unpleasant experience dealing with this company. I don't have an account with them, yet I am receiving sms's for another of their customers. I have been into the Greenacres branch to lay a complaint; mind you, this has been ongoing since June. I have spoken to so many different people, including the regional manager an have been promised on so many occasions that the problem would be sorted out. Yet, I'm still receiving the messages for a Mr. Mhaule!!! I've even been contacted by the Cape Town office and told that I would no longer have this issue, but today I received another sms demanding payment on his account. I'm so fed up with all of this because I've been going into the branch, almost twice a month since the onset, to try and get them to rectify this issue and still it persists. I'm now at my wits end and don't know what to do anymore? I want this issue sorted out!!!!