Number Defect

I changed my cellphone nr after I was harassed. After I complained at Mimosa Mall Branch in Bloemfontein where they couldn't assist me they referred me to the Main Branch in Nelson Mandela Avenue Bloemfontein, where they informed me contact 808 and 808 referred me to *141*5# but I couldn't get hold of them. At the Main Branch they informed me that they can't help me to get rid of my problem. The only thing I want is to get a new number without defects so that I can be able to use my phone in a proper way, for the 2 year contact that I have with it. The problems that occur is that the voice mail is not mine and I can't get rid of it or change it and furthermore there is this very strange musical message people ho phone me receive. Is it possible that you can assist me in this regard. Thank you very much. Mrs M. Jacobs